Application Finder
- 8.000.6011Ion chromatographic determination of anions, cations and organic acids in biofuels
Quality and process control of biofuels require straightforward, fast and accurate analysis methods. Ion chromatography (IC) is at the leading edge of this effort. Traces of anions in a gasoline/ethanol blend can accurately be determined in the sub-ppb range after Metrohm Inline Matrix Elimination using anion chromatography with conductivity detection after sequential suppression. While the analyte anions are retained on the preconcentration column, the interfering organic gasoline/bioethanol matrix is washed away.Detrimental alkali metals and water-extractable alkaline earth metals in biodiesel are determined in the sub-ppm range using cation chromatography with direct conductivity detection applying automated extraction with nitric acid and subsequent Metrohm Inline Dialysis. Unlike high-molecular substances, ions in the high-ionic strength matrix diffuse through a membrane into the low-ionic water acceptor solution. In biogas reactor samples, low-molecular-weight organic acids stem from the biodegradation of organic matter. Their profile allows important conclusions concerning conversion in the anaerobic digestion reaction. Volatile fatty acids and lactate can be accurately determined by using ion-exclusion chromatography with suppressed conductivity detection after inline dialysis or filtration.
- 8.000.6012Automated logical dilution for ion chromatographic determinations
The combination of 850 Professional IC, 858 Professional Sample Processor, Dosino and MagIC NetTM software offers a variety of sophisticated ion chromatographic sample preparation techniques. One of these is the automated inline dilution of samples.After the first sample injection, MagIC NetTM verifies if the area of the sample peak lies within the calibration range. If the measured peak area is outside these limits, the software calculates the appropriate dilution factor, dilutes and automatically re-injects the sample. For all investigated ions (Li+, Na+, K+, Ca2+, Mg2+, F-, Cl- , NO2-, Br-, NO3-, SO42- ), automated logical dilution yielded coefficients of determination (R2) better than 0.9999. Direct-injection recoveries for cations and anions were within 98.6…99.5% and 93.4…100.4% respectively. In contrast, after logical dilution, recoveries for cations and anions were within 100.1…102.9% and 98.2…102.6% respectively. The relative standard deviations for all determinations involving diluted sample solutions were smaller than 0.91%.
- 8.000.6014Determination of anions and cations in aerosols by ion chromatography
The study of adverse effects of air pollution requires semi-continuous, rapid and accurate measurements of inorganic species in aerosols and their gas phase components in ambient air. The most promising instruments, often referred to as steam collecting devices, are the Particle-Into-Liquid-Sampler (PILS) coupled to wet-chemical analyzers such as a cation and/or anion chromatograph (IC) and the Monitoring instrument for AeRosols and GAses (MARGA) with two integrated ICs. Both instruments comprise gas denuders, a condensation particle growth sampler as well as pump and control devices. While PILS uses two consecutive fixed denuders and a downstream growth chamber, the MARGA system is composed of a Wet Rotating Denuder (WRD) and a Steam-Jet Aerosol Collector (SJAC). Although the aerosol samplers of PILS and MARGA use different assemblies, both apply the technique of growing aerosol particles into droplets in a supersaturated water vapor environment. Previously mixed with carrier water, the collected droplets are continuously fed into sample loops or preconcentration columns for on-line IC analysis. While PILS has been designed to sample aerosols only, MARGA additionally determines water-soluble gases. Compared to the classical denuders, which remove gases from the air sample upstream of the growth chamber, MARGA collects the gaseous species in a WRD for on-line analysis. In contrast to the gases, aerosols have low diffusion speeds and thus neither dissolve in the PILS denuders nor in the WRD. Proper selection of the ion chromatographic conditions of PILS-IC allows a precise determination, within 4 to 5 minutes, of seven major inorganic species (Na+, K+, Ca2+, Mg2+, Cl-, NO3- and SO4 2-) in fine aerosol particles. With longer analysis times (10-15 minutes) even airborne low-molecular-weight organic acids, such as acetate, formate and oxalate can be analyzed. MARGA additionally facilitates the simultaneous determination of HCl, HNO3, HNO2, SO2 and NH3.PILS and MARGA provide semi-continuous, long-term stand-alone measurements (1 week) and can measure particulate pollutants in the ng/m3 range.
- 8.000.6015Effect of eluent composition and column temperature on IC column retention times
This work was carried out with a Metrosep C 2 - 150 separation column, the following eluent parameters being investigated: nitric, tartaric, citric and oxalic acid concentration and concentration of the complexing anion of dipicolinic acid (DPA). The aim was to determine the effect of these parameters plus that of the column temperature on the retention times of alkali metals, alkaline earth metals, ammonium and amines using ion exchange chromatography with non-suppressed conductivity detection. Due to similar affinities for the ion exchange column, transition metals are difficult to separate with the classical nitric, tartaric, citric and oxalic acid eluents. Partial complexation with the dipicolinate ligand significantly shortens the retention times and improves the separation efficiency. However, too strong complexation results in a rapid passage through the column and thus in a complete loss of separation. Apart from a change in the elution order of magnesium and calcium at high DPA concentrations, other non-amine cations are only slightly affected by the eluent composition. Irrespective of the tartaric acid and nitric acid concentration in the eluent, an increase in column temperature shortens the retention times and slightly improves the peak symmetries of organic amine cations, particularly in the case of the trimethylamine cation. In contrast, an increase in column temperature in the presence of DPA concentrations exceeding 0.02 mmol/L increases the retention time of the transition metals. Depending on the separation problem, variation of the pH value, the use of a complexing agent and/or an increase in column temperature are powerful tools for broadening the scope of cation chromatography.
- 8.000.6034Determination of the sodium contribution of solvent-extractable organic compounds in Bayer process liquor
This poster presents a highly reproducible procedure for the determination of the sodium contribution of acid-extractable organic species in Bayer process liquor. The precision of the method is estimated to be 0.2% RSD.
- 8.000.6040Improved cation separation thanks to a new column material
Comparative measurements show that the new Metrosep C 4 cation column has even better separation characteristics than the previous Metrosep C 2 and Metrosep Cation 1-2 column types. The Metrosep C 4 column has a clearly improved peak shape which leads to a better separation of the individual peaks. Using Metrosep C 4 the number of theoretical plates per meter was noticeably higher than that obtained on the Metrosep C 2 or C 1-2 column. Additionally for standard cations transition metals and amines, the Metrosep C 4 column shows better results with respect to peak shape, peak height, resolution and asymmetry factor. The clearly improved resolution of the C 4 column with its narrow and high peaks achieves baseline separation for six standard and six transition metal cations. Analysis times and peak areas obtained with the C 4 column are in the same range as those obtained with its predecessors.As a result of the latest production methods and materials, the promising Metrosep C 4 column excels by an outstanding separation performance for complex mixtures comprising standard cations, transition metal cations and amines.
- 8.000.6042Straightforward multipoint calibration using a single standard
The combination of 850 Professional IC, 858 Professional Sample Processor, Dosino and MagIC NetTM software offers a variety of automated ion chromatographic sample preparation and calibration techniques available as an anion, cation or dual channel system. Calibration is straightforward and requires only one multi-ion standard.Inline calibration allows the calibration of any standard concentration in the ppt range by using one single stable standard solution at the ppb level. By using a preconcentration column and switching the valves one, two or more times different calibration concentrations at the ultra-trace level can be created with unprecedented reproducibility. The inline preconcentration technique uses a pre-concentration column and is ideally suited for trace analysis in complex matrices, especially when combined with matrix elimination. Besides facilitating the preparation of g/L to ng/L calibration graphs Metrohm`s intelligent techniques are capable of logical decision making. While Metrohm`s intelligent Partial Loop technique (MiPT) allows samples with a wide concentration range to be injected without previous manual dilution, the intelligent inline dilution technique, after the first sample injection, compares peak areas, calculates, if necessary, the dilution factor, dilutes and automatically re-injects the sample. The presented inline techniques allow the rationalization of the time-consuming, error-prone and cost-intensive manual preparation of standard solutions. They guarantee that the determined sample concentrations always lie within the calibration range. Higher sample throughputs as well as lower analysis costs and improved data reliability are achieved.
- 8.000.6044Fully automated sample preparation for liquid chromatographic content determinations
Inline coupling of the 815 Robotic Soliprep with an ion chromatograph (IC) allows the straightforward determination of anions and cations in tablets. After automatic solvent addition and subsequent comminution, the homogenized tablet samples (Singulair and Bezafibrat) are filtered and subsequently transferred to the injector. The completely automated sample preparation saves both time and money, guarantees traceability of each sample preparation step and yields correct and precise results. In the range of 0.2…50 mg/L, six-point calibration curves for anions and cations yield correlation coefficients better than 0.99990 and 0.99991, respectively. While relative standard deviations (RSDs) for sub-ppm levels of nitrate, sulfate, calcium and magnesium in Singulair and Bezafibrat are smaller than 3.64%, RSD of ppm levels of chloride is better than 0.83%. The application of further inline sample preparation steps such as pulverizing, extracting, filtering or diluting facilitates numerous custom-tailored setups for ion determinations in exacting matrices such as animal feed, sediments or food.
- 8.000.6052Quality assurance of biofuels
This poster provides an overview of ion chromatographic methods combined with inline sample preparation for the determination of anions and water-extractable cations in biofuels. In addition, the determination of the oxidation stability is described.
- 8.000.6055Liquid handling applied to automated sample preparation in liquid chromatography
In routine chemical analysis, the predominant challenge involves a higher sample throughput, improved reproducibility, liquid handling flexibility and reduced personnel costs. In response to these requirements, the 872 Extension Module Liquid Handling in combination with the MagIC NetTM software and the well-proven Dosino technology expands the possibilities of inline sample preparation and opens up new fields of application. Among others, the module can be used, together with an optional mixing vessel, for pH adjustments, pre-column derivatizations, or the mixing of solutions.As a representative of an inline sample preparation technique, this poster describes the performance of precise dilutions. By using only one single stable standard solution, multi-point calibration curves can be automatically recorded by diluting a concentrated standard in an external vessel.
- 8.000.6072Trace-level determination of cations in the secondary circuit of a PWR-type nuclear power plant using ion chromatography after inline sample preparation
The presented IC system with inline sample preparation allows the determination of traces of lithium and sodium (ppt) in the presence of ppm quantities of ammonium and ethanolamine.
- 8.000.6086Semi-continuous determination of anions, cations, and heavy metals in aerosols using PILS-IC-VA
This poster presents an approach that couples a Particle-Into-Liquid-Sampler (PILS) to a dual-channel ion chromatograph (IC) for measurement of aerosol anions and cations and a voltammetric measuring stand (VA) to determine the heavy metals. Feasibility of the PILS-IC-VA online system was demonstrated by collecting aerosol samples in Herisau Switzerland, at defined time intervals; air pollution events were simulated by burning lead- and cadmium-coated sparklers.
- 8.000.6106Potassium Assay in OTC Drug Products by Ion Chromatography
This poster presented jointly with USP at AAPS meeting shows, that we successfully developed and validated a single IC procedure for potassium assay and identification in potassium bicarbonate and potassium chloride for effervescent oral suspension. The optimized chromatographic conditions could be used for other cationic impurities, such as magnesium, calcium, sodium, and ammonium in potassium bicarbonate and potassium chloride for effervescent oral suspension. Single chromatographic method for assay and identification simplifies the overall QA/QC workflow.
- AB-036Half wave potentials of metal ions for the determination by polarography
In the following tables, the half-wave potentials or peak potentials of 90 metal ions are listed. The half-wave potentials (listed in volts) are measured at the dropping mercury electrode (DME) at 25 °C unless indicated otherwise.
- AB-083Sodium analysis by ion-selective electrode
This document explains how to measure Na ion concentration in diverse matrices with a sodium ion-selective electrode (Na-ISE) using direct measurement and standard addition.
- AB-100Biamperometric determination of potassium and/or ammonium
The potassium (or ammonium) ion is precipitated with sodium tetraphenyl borate, and the excess of this reagent back-titrated against the thallous(I) ion, using biamperometric endpoint detection. Ammonium can either be titrated together in an acid solution, or driven off by previous boiling in an alkaline solution. Methods are given for determining potassium in the presence of large excesses of sodium, ammonium, calcium, and magnesium.
- AB-134Determination of potassium with an ion-selective electrode
Potassium is one of the most common elements and can be found in many different minerals and other potassium compounds. It is of importance for humans, animals and plants as it is an essential mineral nutrient and involved in many cellular functions like cell metabolism and cell growth. For these reasons, it is important to be able to declare the potassium content of food or soil to reduce problems that may arise by a potassium deficiency or extensive consumption.This bulletin describes an alternative to flame photometric method using an ion selective electrode and direct measurement or standard addition technique. Several potassium determinations in different matrices using the combined potassium ion-selective electrode (ISE) are presented here. Additionally, general hints, tips and tricks for best measurement practice are given.
- AB-298Sodium determination in various foods with thermometric titration
In an acidic solution (containing NH4F * HF, Al(NO3)3 / KNO3) sodium forms NaK2AlF6 which precipitates in an exothermic solution, enabling analysis by thermometric titration. Several foods were analyzed, namely bouillon, gravy, tomato ketchup, corn chips, pretzel sticks as well as crackers. The reproducibility of the results was good. After weighing in and adding solutions, samples were crushed with a polytron to ensure homogeneity in the measuring solution. Relative standard deviations were between 0.08% and 3.75%. In addition to this application bulletin, you can find more information on thermometric sodium determination in foods in our application video available on YouTube:https://youtu.be/lnCp9jBxoEs
- AB-343Automated determination of sodium in milk with thermometric titration
This bulletin discusses automated determination of sodium in milk products available to the public using a 859 Titrotherm and a 814 USB Sample Processor. The sodium content of milk can be rapidly and easily titrated thermometrically with a standard solution of Al3+ as titrant. Thermometric titrations are conducted under conditions of constant titrant addition rate. The molarity of the titrant is computed automatically in tiamoTM (software) with the SLO command. Results are reported as mg Na/100 mL. In addition to this application bulletin, you can find more information on thermometric sodium determination in foods in our application video available on YouTube:https://youtu.be/lnCp9jBxoEs
- AN-BAT-013Simultaneous EIS measurements of a Li-ion battery cathode and anode
In battery research, electrochemical impedance spectroscopy (EIS) is a necessary tool to investigate the processes occurring at the electrodes. With a common three-electrode battery, EIS can be performed sequentially first at one electrode and then at the other electrode.
- AN-C-022Sodium, potassium, calcium, and magnesium in a drip feeding formula using dialysis for sample preparation
Determination of sodium, potassium, calcium, and magnesium in a drip feeding formula using cation chromatography with direct conductivity detection and dialysis as sample preparation.
- AN-C-028Four cations in an instant baby milk powder using dialysis for sample preparation
Determination of sodium, potassium, calcium, and magnesium in instant baby milk powder using cation chromatography with direct conductivity detection and dialysis for sample preparation.
- AN-C-038Five cations in 4% boric acid
Determination of sodium, ammonium, potassium, calcium, and magnesium in 4% boric acid using cation chromatography with direct conductivity detection.
- AN-C-049Trace cations in power plant feed water stabilized with 7 ppm monoethanolamine (MEA)
Determination of zinc, lithium, cobalt, sodium, ammonium, potassium, manganese, magnesium, and calcium in power plant feed water stabilized with 7 ppm monoethanolamine using cation chromatography with direct conductivity detection.
- AN-C-055Determination of lead, zinc, indium, cadmium, cobalt, ammonium, potassium, manganese, magnesium, and calcium
Determination of lead, zinc, indium, cadmium, cobalt, ammonium, potassium, manganese, magnesium, and calcium using cation chromatography with direct conductivity detection.
- AN-C-056Sodium, ammonium, methylamine, guanidine, and aminoguanidine in wastewater
Determination of sodium, ammonium, methylamine, guanidine (Gu), and aminoguanidine (Agu) in wastewater using cation chromatography with direct conductivity detection.
- AN-C-059Sodium, ammonium, and potassium in polyethers
Determination of sodium, ammonium, and potassium in polyethers using cation chromatography with direct conductivity detection.
- AN-C-062Five cations including iron in monoethylene glycol (MEG)
Determination of sodium, potassium, iron(II), magnesium, and calcium in an extract of monoethylene glycol using cation chromatography with direct conductivity detection.
- AN-C-064Five cations in betaine
Determination of sodium, ammonium, potassium, calcium, and magnesium in betaine using cation chromatography with direct conductivity detection.
- AN-C-066Four cations in the water soluble fraction of a washing powder
Determination of sodium, potassium, calcium, and magnesium in the water soluble fraction of a washing powder using cation chromatography with direct conductivity detection.
- AN-C-067Cations in grapefruit soft drink using inline dialysis
Determination of sodium, ammonium, potassium, calcium, and magnesium in a grapefruit soft drink using cation chromatography with direct conductivity detection after advanced dialysis for inline sample preparation.
- AN-C-068Cations in functional fruit juice using inline dialysis
Determination of sodium, ammonium, potassium, calcium, and magnesium in a functional fruit juice using cation chromatography with direct conductivity detection after advanced dialysis for inline sample preparation.
- AN-C-069Zinc, sodium, calcium, and magnesium in an industrial bath
Determination of zinc, sodium, calcium, and magnesium in an industrial bath containing cooling lubricants using cation chromatography with direct conductivity detection.
- AN-C-070Cations and biogenic amines in wine
Determination of sodium, potassium, calcium, magnesium, putrescine, cadaverine, and histamine in a wine sample using cation chromatography with direct conductivity detection.
- AN-C-071Choline in a saline solution
Determination of sodium, potassium, DMEA (dimethylethanolamine), calcium, choline, and magnesium in a saline solution using cation chromatography with direct conductivity detection.
- AN-C-083Online monitoring of trace levels of cations in boiler feed water
Determination of trace levels of lithium, sodium, ammonium, potassium, magnesium, and calcium in boiler feed water using cation chromatography with direct conductivity detection.
- AN-C-086Zinc and standard cations in infusion solutions
Determination of zinc, sodium, potassium, magnesium, and calcium in an infusion solution using cation chromatography with direct conductivity detection.
- AN-C-097Cations in ethanol used as biofuel
Determination of traces of lithium, sodium, ammonium, potassium, calcium, and magnesium in ethanol using cation chromatography with direct conductivity detection after Metrohm Inline Matrix Elimination.
- AN-C-101Cations in biodiesel with fully automated aqueous extraction and subsequent dialysis
Determination of potassium, magnesium, and calcium in biodiesel using cation chromatography with direct conductivity detection applying automated extraction and subsequent Metrohm Inline Dialysis.
- AN-C-102Standard cations in orange juice
Determination of sodium, potassium, magnesium, and calcium in orange juice using cation chromatography with direct conductivity detection applying automated dilution and subsequent Metrohm Inline Ultrafiltration.
- AN-C-103Standard cations in lake water on the Metrosep C 3 - 250/4.0 column
Determination of lithium, sodium, potassium, magnesium, and calcium in lake water using cation chromatography with direct conductivity detection.
- AN-C-112Inline eluent preparation for cation analysis
Long-term determination of standard cations with automatic inline eluent preparation using Dosino and Level Control instruments and cation chromatography with direct conductivity detection.
- AN-C-113Determination of lysine and standard cations in a lysine sample
Determination of lysine as well as sodium, ammonium, potassium, and calcium in bulk lysine using cation chromatography with direct conductivity detection.
- AN-C-114Semi-continuous determination of cations in aerosol using PILS-IC
Determination of sodium, ammonium, potassium, magnesium, and calcium in an ambient aerosol (PM2.5) using aerosol sampling with the PILS (Particle Into Liquid Sampler) and cation chromatography with direct conductivity detection.
- AN-C-115Five cations in tap water
Determination of lithium, sodium, potassium, calcium, and magnesium in tap water using cation chromatography with direct conductivity detection.
- AN-C-116Sodium and potassium in toothpaste
Determination of sodium and potassium in toothpaste using cation chromatography with direct conductivity detection.
- AN-C-117MiPT – Metrohm intelligent Partial Loop Technique
Calibration of lithium, sodium, ammonium, zinc, potassium, magnesium, and calcium using the partial loop technique and cation chromatography with direct conductivity detection. This technique allows a calibration range of 1:100 (e.g. 1 μg/L to 100 μg/L corresponding to 2 μL to 200 μL injected volume) out of 1 calibration solution. Applying the full range of partial loop injection to the samples one calibration covers a sample concentration range of 1 to 10'000 e.g. 2 μL of a 10 mg/L solution corresponds to the highest calibration level (100 μg/L) while 200 μL of a 1 μg/L solution corresponds to the lowest calibration level.
- AN-C-118Impurities in syringe filters – Cations
Determination of lithium, sodium, ammonium, zinc, potassium, magnesium, and calcium impurities in syringe filters using cation chromatography with direct conductivity detection.
- AN-C-122Cations including total iron content in antifreeze (monoethylene glycol)
Determination of sodium, potassium, iron(II), magnesium and calcium in antifreeze (monoethylene glycol) using cation chromatography with direct conductivity detection. Ascorbic acid reduces iron(III) to iron(II). In this way total iron is determined as iron(II).
- AN-C-123Cations including strontium in brine
Determination of lithium, sodium, ammonium, potassium, calcium, magnesium, and strontium in brine using cation chromatography with direct conductivity detection.
- AN-C-129Nine cations on the Metrosep C 4 - 150/4.0 column
Determination of lithium, sodium, ammonium, potassium, manganese, calcium, magnesium, strontium, and barium using cation chromatography with direct conductivity detection.
- AN-C-130Cations in offshore effluent
Determination of lithium, sodium, ammonium, potassium, manganese, calcium, magnesium, strontium, and barium in an offshore effluent using cation chromatography with direct conductivity detection.
- AN-C-132Traces of lithium, sodium, and ammonium in the presence of ethanolamine (Metrosep C 4 - 250/4.0)
Determination of lithium, sodium, ammonium, and monoethanolamine (MEA) using cation chromatography with direct conductivity detection and Metrohm Inline Preconcentration and Inline Calibration.
- AN-C-133Tap water analysis for cations using Metrohm intelligent Partial Loop Technique (MiPT)
Partial loop injection is a well known way of sample introduction to HPLC. In ion chromatography, it is not yet used to a large extent. Liquid handling with Metrohm's Dosino technology now enables to use partial loop injection on a highly reproducible and accurate level. It includes multi-level calibration out of one standard solution. This Application Note shows its use for parallel anion and cation determination in tap water applying one single Sample Processor. The anion results are shown in Application Note S–287.
- AN-C-134Cation Inline Eluent Preparation using an 849 Level Control.
Eluent preparation on demand (EPOD) is the convenient and flexible way of automatic eluent preparation. The 849 Level Control together with an 800 Dosino equipped with a 50 mL dosing unit are used to dilute an eluent concentrate to the required eluent concentration. The use of eluent concentrates is suitable for any eluent. This facilitates unattended operation of the system over several weeks (see AN S-296 for anion eluent preparation).
- AN-C-135Cations in drinking water using Metrosep C 4 - 150/4.0 column according to ISO 14911.
Drinking water analysis is strongly regulated by standards. In this Application Note, the cation determination according to ISO 14911 is shown. The Metrosep C 4 - 150/4.0 is the optimum separation column for this purpose.
- AN-C-136Metrohm intelligent Partial Loop Technique (MiPT) – a single standard calibration: 2 mL vs. 5 mL Dosing Unit
Metrohm intelligent Partial Loop Technique (MiPT) is a versatile injection mode in IC. In this application, injection volumes range from 4 to 200 µL (corresponding to 0.5 - 10 mg/L) using the 250 µL loop. Here, the use of 2 and 5 mL Dosing Units are compared.
- AN-C-137Copper, nickel, zinc, and common cations in the water-steam cycle of a boiling water reactor (BWR)
Water chemistry of the water-steam cycle is crucial for maintaining plant reliability and for ensuring optimal plant operational conditions. Impurities such as corrosion products in ionic, colloidal, or oxide forms are ubiquitous in feedwater, condensate, and reactor coolant. This application shows the determination of sub-ppb levels of Cu, Ni, Zn and standard cations (e.g., Na+, NH4+, Mg2+, Ca2+) in the water-steam cycle of a BWR.
- AN-C-139Cations and amines in the water-steam cycle
Water in steel-based cooling systems requires a pH value slightly above 7 to prevent corrosion. Often ammonium or organic amines are applied for pH adjustement. This application shows the separation of typical amines besides inorganic cations. Sample preconcentration applies combined Inline Preconcentration and Matrix Elimination (MiPCT-ME).
- AN-C-140Lithium in borated water of a pressurized water reactor (PWR)
In pressurized water reactors (PWRs), light water is used as coolant in the primary side. Boron (as boric acid) is added to the coolant to absorb neutrons, thus controlling reactivity. Lithium hydroxide assures the alkaline pH value to prevent corrosion. This application allows to measure lithium content besides high boric acid concentrations. AN-C-138 shows the respective trace metal determination on the same system setup.
- AN-C-141Cations in small sample volumes by using the intelligent Pick-up Injection Technique (MiPuT)
The determination of cations in tap water is a simple IC application. Here it is used to present Metrohm's intelligent Pick-up Technique (MiPuT). MiPuT enables the injection of volumes of minimum size from very small sample quantities. In the present case, two volumes of 10 µL from a sample 100 µL in size are used for anion and cation analysis, respectively. The calibration takes place through the injection of various volumes of a single standard solution. AN-S-302 describes the corresponding anion determination.
- AN-C-142Separation of the standard cations on the high-capacity Metrosep C 6 separation columns
The Metrosep C 6 columns have a higher capacity than those of the Metrosep C 4. The present Application Note describes the exceptional separating efficiency for standard cations with the three Metrosep C 6 column lengths available. The outstanding sodium-ammonia separation is particularly noteworthy.
- AN-C-143Ammonia in addition to standard cations in maritime pore water
Maritime pore water contains sodium in the percentage range. The analysis of ammonia in this kind of sample requires a high column capacity and an exceptionally good separation of sodium and ammonia. These requirements are completely fulfilled by a 2 µL injection to the high-capacity Metrosep C 6 - 250/4.0 column.
- AN-C-144Variable Inline Preconcentration including matrix elimination for trace cation determination (MiPCT-ME)
Metrohm Inline Preconcentration Technique with matrix elimination (MiPCT-ME) is a powerful method that combines preconcentration, matrix elimination, and multilevel calibration. In this Application Note, the methodology is applied to the determination of traces of sodium in addition to 2 mg/L ammonia. The Metrosep C 6 - 250/4.0 column is used for selectivity reasons.
- AN-C-145Ammonium traces besides excess sodium using 940 Professional IC Vario and direct conductivity detection
The determination of low ammonium concentrations besides excess sodium is demanding due to the small retention time difference of these two cations. This Application Note shows direct conductivity detection as an ideal means to detect ammonium in a wastewater sample containing 400 mg/L sodium. AN-S-313 shows the analysis of nitrite traces.
- AN-C-147Fast analysis of cations in tap water using Metrosep C 4 - 100/2.0
Reducing the analysis time is a demanding task because it is accompanied by a parallel reduction of peak resolution. With a Microbore column 100 mm in length, standard cations in tap water can be determined in only 5 minutes. Strontium can also be determined by simply extending the run time to 6.5 min.
- AN-C-148Metrohm Inline Dilution – Dilution factors of up to 10,000 in two intelligent steps
Sample dilution is a work-intensive routine task in the analysis laboratory. An automatic two-step dilution exponentiates the dilution factor – 1:100 – thus incorporating a dilution factor of 10,000. The intelligent dilution is made possible by MagIC Net, which calculates the essential dilution steps, and by the dosing properties of the 800 Dosino and the Liquid Handling Station. The Application Note shows statistical results of a 1:10,000 dilution.
- AN-C-149Determination of cations on surfaces of printed circuit boards
Cleanliness is indispensable in electronics production. Ionic contaminations in particular lead to a drastic worsening of the quality of the printed circuit boards. The present Application Note describes the determination of cations on printed circuit board surfaces. The intelligent Partial Loop Injection Technique (MiPT) used for this purpose permits the determination of cations and anions in the same sample. The determination of the anions is described in AN-S-317.
- AN-C-150Fast IC: Separation of standard cations in eleven minutes
Fast IC means short run times on separation columns with a relatively high flow rate and the standard eluent. Here the standard cations are separated within eleven minutes on the Metrosep C 4 - 250/2.0. The sodium and ammonium peaks are separated from one another under these conditions.
- AN-C-151Fast IC: Separation of standard cations in five minutes
Fast IC means short run times on separation columns with a relatively high flow rate. Separation with the Metrosep C 4 - 150/2.0 is even quicker than that in the AN-C-150 at 1.1 mL/min. Here, the standard cations are separated within five minutes. Under the selected conditions, sodium and ammonium are no longer completely separated.
- AN-C-154Fast IC: Cations in drinking water on a high-capacity column in eleven minutes
Fast and handsome IC! Outstanding peak shapes on columns with the standard flow rate and a strong eluent. When the high-capacity Metrosep C 6 - 250/4.0 is used, this usually means long retention times. A strong eluent allows however the determination of the cations in drinking water in a short run time with very symmetrical peaks.
- AN-C-157Sodium and potassium in polyol using IC following inline matrix elimination
Polyols are important raw materials in polyurethane production. Contamination in the raw materials have a great influence on reactions and impair the quality of the end product. Alkali metals are particularly strong catalysts for linear or branched reactions. A rapid and precise method for their simultaneous determination is ion chromatography following Inline Matrix Elimination.
- AN-C-158Column stability of the Metrosep C 6 - 250/4.0 with Inline Ultrafiltration and Inline Eluent Preparation
The column stability of the Metrosep C 6 - 250/4.0 was determined in long-term laboratory tests. Two injection series per day were run on each of six days in a row. Each series was comprised of nine tap water injections, three check standard injections and six tap water injections. The IC system was shut down on the seventh day of each series. As a whole, the system ran over 10 weeks and counted a total of 2,150 injections. The results show an outstanding reproducibility and verify the high column stability.
- AN-C-159Cation traces on the Metrosep C 4 - 250/2.0 column after Inline Preconcentration with matrix elimination
Intelligent Inline Preconcentration with Inline Matrix Elimination (MiPCT-ME) is used for trace determination of the six standard cations in addition to zinc and diethylamine. The analysis is completed within 24 minutes on the Metrosep C 4 - 250/2.0 Microbore column. The recovery rates are in excess of 95%. The detection limits calculated with the MagIC Net software are in the lower ng/L range for a preconcentration volume of 4 mL.
- AN-C-161Trimethylamine N-oxide and biogenic amines in addition to standard cations in white wine
Biogenic amines and trimethylamine N-oxide (TMAO) are indicators for the quality of grape fermentation. The consumption of amine-rich wines often leads to headaches, which is why the amine concentrations in wine must be monitored. This Application Note describes the determination of trimethylamine N-oxide, putrescine, cadaverine and histamine, in addition to various standard cations, with the aid of the Metrosep C 6 - 100/4.0 column and subsequent direct conductivity detection.
- AN-C-163Cations in brine with minimal dilution and sub-µL injection
As a rule, brine samples are diluted extremely in order to avoid overloading the column. Manual dilution is very error-prone, which is why this application relies on injection with a 0.25 µL internal loop, thus saving an additional dilution step. Sodium, potassium, magnesium and calcium in brine are determined on a Metrosep C 6 - 150/4.0 column with subsequent direct conductivity detection.
- AN-C-164Amine analysis in gas scrubber solutions from refineries with direct conductivity detection
In natural gas production, the removal of contaminants, and in particular acidic gases such as H2S and CO2, is exceptionally important. These acidic gases are removed in the amine wash through chemical treatment with amines or alkanol amines. This application shows a convenient and precise analysis with the separation of various amines and standard cations on a column of the Metrosep C 6 - 250/4.0 type with subsequent direct conductivity detection.
- AN-C-165Triethylamine in aqueous 1,3,5-trioxane solution with direct conductivity detection
1,3,5-trioxane is a heterocyclic compound formed by trimerization of formaldehyde. Trioxane is used for the production of polyformaldehyde plastics such as poly(oxymethylene) (POM) and solid fuels. Aqueous 1,3,5-trioxane solutions frequently contain trace triethylamine that requires quantification. This is performed on the Metrosep C 3 - 250/4.0 column with subsequent direct conductivity detection.
- AN-C-169Determination of cations in tobacco additives
Tobacco additives may contain cations like ammonium (see AN-C-168) as well as other cations as counter ions of organic acids. These additives include components to retain moisture and flavor of the tobacco. Ammonium is added to increase the appeal of smoking, and is therefore considered to increase the addictive potential. The determination of cations in tobacco additives is performed by ion chromatographic separation followed by non-suppressed conductivity detection.
- AN-C-170N-methyldiethanolamine, piper-azine and standard cations in scrubber solutions
N-methyldiethanolamine and piperazine are used in scrubber solutions, e.g., in the natural gas process. Testing this type of samples by ion chromatography requires a good resolution and the separation of amines from standard cations. The separation is achieved on a Metrosep C 4 - 150/4.0 column applying direct conductivity detection.
- AN-C-172Cations in snow from an open field
Cation content in snow is greatly dependent on sampling site. Samples from remote areas are expected to exhibit lower cation concentrations. This application shows the analysis of a snow sample from an open field in an agricultural zone. Separation is performed on a microbore Metrosep C 6 - 100/2.0 column with direct conductivity detection. The relatively high ammonia content can be explained by animal husbandry in the vicinity of the sampling site.
- AN-C-173Cations in roadside snow
Cation content in snow is greatly dependent on sampling site. Roadside samples are likely to exhibit a high sodium content caused by the use of road salt. This application shows the analysis of a snow sample from a roadside. Separation is performed on a microbore Metrosep C 6 - 250/2.0 column with direct conductivity detection. The 250 mm column was selected due to the large difference in concentrations between sodium and ammonia. This condition enables a baseline separation of the two cations.
- AN-C-174Rapid determination of cations in drinking water on a microbore separation column
Cation analysis in drinking water is a routine task in ion chromatography and can be achieved with a variety of separating columns. The use of a microbore Metrosep C 6 - 250/2.0 column with a high eluent concentration makes it possible to reduce analysis time to less than 12 minutes. Very symmetrical peaks with high sensitivity for the divalent cations are also achieved. Direct conductivity detection is applied.
- AN-C-175Purity of 2-amino-N-(2,2,2-trifluoroethyl)-acetamide by ion chromatography
2-amino-N-(2,2,2-trifluoroethyl)-acetamide is a organic building block for synthesis of pharmaceutical products. Its purity is crucial for the success of the respective synthesis step. 2,2,2-trifluoroethylamine, glycine, and inorganic cations are of interest. Their total peak area is required to be < 2 % of the peak area of all peaks above the reporting level. Separation and quantification is achieved on a Metrosep C 4 - 250/4.0 cation column.
- AN-C-178Aspartic acid, glutamic acid, TRIS, sodium, and potassium in cardioplegic solution
A cardioplegic solution protects the ischemic myocardium from cell death. It is applied together with hypothermia e.g. in open heart surgery. Here the simultaneous determination of aspartic acid, glutamic acid, tris(aminomethyl)aminomethane (TRIS), sodium and potassium in such a solution is given. The two amino acids can be determined as they are partially in the triple protonated ammonium form at the eluent pH. Determination is achieved by direct conductivity detection.
- AN-C-179Cations and lactic acid in whey powder applying two separation mechanisms in the same analysis
Whey is the remaining liquid after cheese production. It is mainly used as feed. It is also used as dietary supplement as a beverage or in powder form. This application determines lactic acid as well as cations in one determination. The Metrosep C 6 - 250/4.0 column separates sodium, potassium, magnesium, and calcium by ion exchange. It also acts as an ion-exclusion column, which separates lactic acid. Both lactic acid and the cations can be determined in the same run applying direct conductivity detection. While cations typically elute as negative peaks, lactic acid elutes as an early positive peak. MagIC Net shows both in the usual positive direction.
- AN-C-181Potassium in potassium bitartrate as per USP
Within the scope of the USP monograph modernization, potassium is determined in potassium bitartrate applying cation chromatography with direct conductivity detection. The USP41 monograph for “Potassium bitartrate” does not yet mention an assay for potassium. The separation is performed on a Metrosep C 6 - 150/4.0 column (L76). The assay of potassium is performed with two commercially available products according to USP definitions. All acceptance criteria are fulfilled.
- AN-C-182Potassium in potassium sodium tartrate as per USP
Within the scope of the USP monograph modernization, potassium is determined in potassium sodium tartrate applying cation chromatography with direct conductivity detection. The USP41 monograph for “Potassium sodium tartrate” does not yet mention an assay for potassium. The separation is performed on a Metrosep C 6 - 150/4.0 column (L76). The assay of potassium is performed with two commercially available products according to USP definitions. All acceptance criteria are fulfilled.
- AN-C-183Potassium in potassium bicarbonate effervescent tablets for oral solution
Within the scope of the USP monograph modernization, potassium is determined in potassium bicarbonate effervescent tablets for oral suspension applying cation chromatography with direct conductivity detection. The separation is performed on a Metrosep C 6 - 150/4.0 column (L76). All acceptance criteria are fulfilled.
- AN-C-184Potassium and sodium bicarbonates and citric acid effervescent tablets for oral solution
As an alternative to flame photometry, ion chromatography with non-suppressed conductivity detection has been approved by the USP as a validated method to quantify potassium and sodium content in potassium and sodium bicarbonates and citric acid effervescent tablets for oral solution. The present IC method has been validated according to USP General Chapter <621>.
- AN-C-185Potassium in potassium bicarbonate and potassium chloride effervescent tablets for oral solution
As an alternative to flame photometry, ion chromatography with non-suppressed conductivity detection has been approved by the USP as a validated method to quantify potassium content in potassium bicarbonate and potassium chloride effervescent tablets for oral solution. The Metrosep C 6 - 150/4.0 column (L76) provides the required separation of potassium and magnesium. The present IC method has been validated according to USP General Chapter <621>.
- AN-C-186Sodium in potassium sodium tartrate as per USP
Within the scope of the USP monograph modernization, sodium is determined in potassium sodium tartrate applying cation chromatography with direct conductivity detection. The USP41 monograph for «Potassium sodium tartrate» does not yet mention an assay for sodium. The separation is performed on a Metrosep C 6 - 150/4.0 column (L76). The assay of potassium is performed with two commercially available products according to USP definitions. All acceptance criteria are fulfilled. See AN-C-182 for the respective determination of potassium. Apllying this method allows to determine sodium and potassium simultaneously according to USP.
- AN-C-188Ammonium impurities in potassium bitartrate
Potassium bitartrate for pharmaceutical use must comply with USP requirements. The actual monograph (USP 42) uses a colorimetric method for the determination of ammonium impurities. Ion chromatography allows the measurement in a single determination under the same conditions used for the potassium assay (see AN-C-181). In the course of the USP monograph modernization, this ion chromatographic approach makes this type of analysis even easier.
- AN-C-189Cations in lithium ore
The exploration and processing of lithium ores is gaining importance with the growing demand for lithium hydroxide. Lithium hydroxide is a key component in the manufacturing of rechargeable batteries for use in various applications including electric vehicles, home storage systems, power tools and consumer electronics. To ensure the efficiency for advanced processing of high purity lithium hydroxide, a fast and reliable quantitative detection technique is required. This application has been developed to monitor the lithium, sodium, and calcium content in the lithium processing samples and mineral concentrates.
- AN-C-190Analysis of amine emulsifiers besides standard cations
Isopropylamine and dicyclohexylamine are used as emulsifiers and need to be determined in emulsions along with standard cations. However, emulsions must not be injected directly into the ion chromatograph as the organic components may damage the ion exchanger stationary phase in the separation column. Inline Dialysis as sample preparation is the perfect tool for such samples. The ions of interest are separated from the organic phase by diffusion through the hydrophilic membrane, thus protecting the column. Full automation makes the analyses even easier and more efficient for the user.
- AN-C-191Sodium in lanthanum acetate
Lanthanum (La) is a transition metal which oxidizes easily in air to lanthanum(III) oxide. This oxide, as well as salts resulting from its dissolution in acid and recrystallization, is a component of different catalysts. Here, a lanthanum(III) acetate solution prepared by dissolution of lanthanum(III) oxide in acetic acid, has to be tested for a sodium contamination. The high concentration of La3+ is complexed by the dipicolinic acid in the eluent and forms anionic complexes. These complexes are eluted in the front and therefore do not interfere with the sodium impurity as well as other cations such as ammonium and calcium.
- AN-C-192Cations in sodium rich wastewater
Wastewaters often contain high loads of sodium, making the determination of minor cations quite a challenge. In the present wastewater study, the determination of lithium, ammonium, zinc, strontium, and barium is requested. If the sodium concentration exceeds 2 g/L, this negatively influences the peak shape of closely eluting peaks. Applying a appropriate dilution factor to the sample enables the quantification of minor cations. Therefore zinc and barium can be properly quantified with a dilution ratio of 1:2, while lithium and ammonium require minimum dilution factors of at least 1:10 and 1:100, respectively.
- AN-C-193Alkyl amines in scrubber solutions
Harmful industrial flue gases like H2S and CO2 cause corrosion of pipes and damage the environment. Adding the correct amount of amines in scrubber solutions, e.g. ethanolamines and methylamines, will neutralize these gases («gas sweetening»). Non-suppressed cation analysis with direct conductivity detection is a straightforward and robust technique for the quantification of monoethanolamine (MEA), diethanolamine (DEA), triethanolamine (TEA), monomethylamine (MMA), dimethylamine (DMA), and trimethylamine (TMA) via ion chromatography. Thanks to the high capacity of the Metrosep C 6 column, large volumes can be injected without compromising the peak shapes. The analytical technique can be used at laboratory scale but also for process analysis.
- AN-C-195Cation quantification with increased performance using microbore IC
Microbore ion chromatography offers better sensitivity, shorter retention times, and consumes less eluent, increasing sample throughput and reducing running costs.
- AN-C-197Potassium assay in potassium citrate and citric acid oral solution
Potassium citrate and citric acid oral solutions act as systemic alkalizers. Potassium assays, validated per USP <621> and <1225>, use IC with L76 cation-exchange columns.
- AN-CS-001Reproducibility of 10 µg/L injections after cation suppression
Cation chromatography with sequential suppression enables the determination of cations in their hydrogen carbonate form. The eluent – usually nitric acid – is converted into carbonic acid. Following its decomposition into carbon dioxide and water, the former is continuously removed by the CO2 suppressor. The reduction of baseline noise thus achieved permits the lowering of the detection limits and improves reproducibility, even at very low cation concentrations. This Note shows the reproducibilities determined for cation concentrations of 10 µg/L.
- AN-CS-006Aliphatic amines and ethanol amines in addition to standard cations by sequential suppression
This Application Note shows the selectivity of the Metrosep C Supp 1 - 250/4.0 column for alkyl and ethanol amines in addition to standard cations under isocratic conditions. Quantification takes place using conductivity detection following sequential suppression.
- AN-CS-007Lithium in addition to other cations in seepage water from minerals through sequential suppression
With the advent of electric automobiles, the demand for lithium batteries and with it the demand for lithium material will increase sharply. Brine lakes and hard silicate minerals are numbered among the most important sources of lithium. This Application Note addresses cation determination in seepage water from lithium minerals. Alkali and earth alkali metals are separated in the lithium digestions on the Metrosep C Supp 1 - 250/4.0 column, with subsequent conductivity detection after sequential suppression.
- AN-CS-009Leaching tests for sample vials in cation trace analysis with sequential suppression
Sequential suppression in cation chromatography significantly improves detection limits. The determination of the blank value of the sample vial being used is thus essential for being able to achieve such low detection limits. The leaching tests of various sample vials proceed with the intelligent Preconcentration Technique with Matrix Elimination on the Metrosep C Supp 1 - 250/4.0 column with conductivity detection following sequential suppression. The 50 mL Corning® Cell Culture Flasks from Sigma-Aldrich (CLS430168) exhibit the lowest blank values.
- AN-CS-010Traces of lithium and sodium besides monoethanolamine in water-steam circuits of thermal power plants
Boiler feed water is a working medium in thermal power plant. To keep corrosion low, the pH value should be in the slightly alkali range, which is why amines are added to the feed water. This addition must be monitored regularly. Also important is the monitoring of the sodium concentration, because an increase of this indicates that cooling water is seeping into the condenser. Ion chromatography with conductivity detection following sequential suppression is the optimum system for monitoring, particularly in combination with intelligent Sample Preconcentration and Matrix Elimination.
- AN-CS-011Cation traces in lithium hexafluorophosphate
Lithium hexafluorophosphate (LiPF6) is used as an electrolyte in rechargeable batteries. Its high solubility in non-polar solvents and its non-coordinating character in particular make lithium hexafluorophosphate the ideal salt for use in lithium-ion cells. This Application describes the determination of cation traces in LiPF6 with conductivity detection following sequential suppression.
- AN-CS-013Cations in deionized water and calculation of LOD and MDL of MiPCT
Trace cation analysis in high purity water (sub-μg/L range) requires cation chromatography after sequential suppression and intelligent Preconcentration Technique (MiPCT). Trace cations in deionized water (DI) are determined and the method detection limit (MDL according to US EPA) as well as the limit of detection (LOD = 3 x S/N) is calculated. MDL and LOD are very similar in the lowest ng/L range for this setup with 6 mL preconcentration volume.
- AN-CS-014Biogenic amines besides other cations in red wine applying a high-pressure gradient
Biogenic amines are released during the winemaking process. In wine, they are present as odorless salts. However, in the mouth their flavor is partially liberated, influencing the appearance for the wine taste. Besides this, biogenic amines have been related to lack of hygiene or poor manufacturing practices. The biogenic amines are determined applying suppressed cation chromatography.
- AN-CS-015Limit of choline in succinylcholine on a Metrosep C Supp 1 - 150/4.0 closely following USP
Succinylcholine is a short-term paralyzing agent used e.g., for tracheal intubation. Choline is a building block of the drug and needs to be determined as an impurity. USP applies cation chromatography with conductivity detection after suppression. Eluent composition and column type do not exactly comply with the USP method. However, the results fulfill the respective requirements. The choline concentration of the sample is out of USP specifications.
- AN-CS-017Metrosep C Supp 2 - 250/4.0: Ammonium in acidic absorption solution – proof of concept
Acidic solutions used as scrubber solutions for ammonium typically have a pH of 2 or lower. This pH value is too low for silica based IC columns typically applied in direct conductivity detection of cations. The Metrosep C Supp 2 - 250/4.0 is polymer based and allows injecting low pH samples. An acidified drinking water sample spiked with ammonium is analyzed. The results indicate that such acidic solutions can be analyzed with conductivity detection after sequential cation suppression.
- AN-CS-018Metrosep C Supp 2 - 250/4.0: Cations in wastewater applying a Dose-in gradient
Cation analysis by IC in wastewater is a proven method. Limiting factor is often the Na/NH4 separation. High sodium concentrations may make ammonium determination impossible due to peak overlapping. The use of sequential suppression and a Dose-in gradient improve the Na/NH4 separation and enables determination of low ammonium concentrations.
- AN-CS-020Fast IC with Metrosep C Supp 2 - 100/4.0: Four cations in five minutes
The short Metrosep C Supp 2 - 100/4.0 allows applying a higher eluent flow. Together with a more concentrated eluent (7.0 instead of 5.0 mmol/L nitric acid) the run time of the four cations, sodium, potassium, magnesium, and calcium can be reduced to 5 minutes. Conductivity detection after sequential suppression is applied.
- AN-CS-021Sodium in sodium bicarbonate and sodium phosphates compounded injections
Compounded injections of sodium bicarbonate are sterile solutions for correcting metabolic acidosis and other conditions requiring systemic alkalinization. Compounded injections of sodium phosphates serve as a phosphate source to either prevent or correct hypophosphatemia in patients with restricted oral intake. Ion chromatography (IC) with suppressed conductivity detection is the standardized way to accurately quantify sodium in these solutions.
- AN-D-001Metrohm IC Driver for OpenLab CDS
This application focuses on the simultaneous analysis of cations and suppressed anions with a dual channel Metrohm IC operated by OpenLab CDS.
- AN-D-002Anions and cations in beer
This Application Note presents ion chromatography as a precise method to analyze anions in beer as well as cations with non-suppressed conductivity. Automation with Inline Ultrafiltration is also discussed.
- AN-D-003Quality control of dialysis concentrates
Ion chromatography (IC) provides an automated, fast, and sensitive solution to accurately quantify cationic and anionic components including acetate simultaneously. This comprehensive approach makes IC an economic alternative to traditional techniques for the quality control of pharmaceutical solutions like haemodialysis concentrates. Ease-of use, accuracy, and the high-throughput of IC increase productivity and comply with the demands of modern routine and research labs.
- AN-EC-034Ion-selective electrodes based on screen-printed technology
Advances in polymeric membranes and screen-printed technologies have enabled miniaturized, portable potentiometric sensors ideal for point-of-care analysis.
- AN-H-007Standardization of sodium tetraphenylborate solution
Standardisation of sodium tetraphenylborate (NaTPB) solution for the determination of potassium and for nonionicsurfactants.
- AN-H-039Determination of sodium lauryl ether sulfate
Determination of sodium lauryl ether sulfate surfactants.
- AN-H-050Determination of sodium and potassium silicates
Determination of sodium, potassium, and silica values in sodium and potassium silicates.
- AN-H-055Analysis of sodium and phosphorus in sodium tripolyphosphate precursor solutions
Determination of Na, P, and [Na]/[P] in precursor solutions and solids in the manufacture of sodium tripolyphosphate.
- AN-H-058Determination of sodium as chloride in ketchup and sauces
Determination of sodium as chloride in ketchups, sauces and, similar food products.
- AN-H-061Direct titration of sodium
Determination of sodium in salts, process solutions, and foods.
- AN-H-062Standardization of titrant for direct titration of sodium
Standardization of titrant for direct determination of sodium.
- AN-H-077Determination of sodium in brines by aluminum titration
Determination of sodium in seawater and similar brines. This procedure is suitable for the analysis of sodium in seawater contaminated with sodium aluminate solutions emanating from alumina refineries, and seawater which has been used for the neutralization of alumina refinery waste («red mud») slurries.
- AN-H-080Determination of total sodium in sodium aluminate liquors by aluminum titration
Determination of the total sodium content of sodium aluminate liquors, such as Bayer Process liquor. This method is suitable for the analysis of all sodium aluminate solutions down to at least 1 g/L as Na2CO3. The determination may be automated by adding an 814 USB sample processor to an 859 Titrotherm.
- AN-H-086Determination of sodium in potato chips
Titration of an unfiltered suspension of the sample with a standardized solution of aluminum containing a stoichiometric excess of potassium ions in the presence of ammonium hydrogen difluoride at ~ pH 3 to give an exothermic reaction, forming insoluble NaK2AlF6. The titrant is standardized against a solution prepared from anhydrous sodium sulfate or sodium carbonate. In addition to this application note, you can find more information on thermometric sodium determination in foods in our application video available on YouTube: https://youtu.be/lnCp9jBxoEs
- AN-H-122Determination of sodium in canned fish products
This Application Note describes the determination of total sodium content in canned fish products using thermometric titration. In addition to this application note, you can find more information on thermometric sodium determination in foods in our application video available on YouTube:https://youtu.be/lnCp9jBxoEs
- AN-H-123Determination of sodium in instant noodles
This Application Note describes the determination of the total sodium content in instant noodles which are also called «two minute noodles» in some countries. These products contain considerable amounts of sodium (at least 50% of the recommended daily dosage), which means that precise analysis of the sodium content is required. Argentometric titration of the chloride content (assuming that the sodium content in the noodles originates exclusively from the sodium chloride that is added to them) is unsuitable for precise analysis, as the nutrient contents listed on the product packaging document the presence of additional sodium salts other than sodium chloride. Thermometric titration enables fast and direct determination of sodium. In addition to this application note, you can find more information on thermometric sodium determination in foods in our application video available on YouTube:https://youtu.be/lnCp9jBxoEs
- AN-H-124Determination of sodium content in the manufacturing of margarine
This Application Note describes the determination of the total concentration of sodium in precursor solutions used in the manufacturing of margarine. The solutions of the precursors are mixed with edible fats and oils to make margarine. Traces of sodium chloride and other sodium and potassium salts may be added to the margarine during this process, usually in the form of emulsifiers, stabilizers, antioxidants, vitamins, coloring agents or flavor enhancers. The analysis of the total sodium content in the precursor solutions is more efficient and cost-effective for the manufacturers than later total sodium content analyses in the final product.As a rule, argentometric titration of chloride is used for indirect determination of the sodium content of foodstuffs. The assumption behind this approach is that the chloride ions are present in a molar ratio of 1:1 with the sodium ions. This is however not the case when – as is usually the case with foodstuffs containing sodium – additional compounds containing sodium are also present in the margarine. The use of potassium chloride as a partial replacement for sodium chloride in some formulations is an additional source of error.The direct titration of sodium by means of thermometric endpoint titration (TET) eliminates these problems. TET is a direct determination method that not only takes into account the entire sodium content present in the solution but is also not hampered by the presence of potassium ions. In addition to this application note, you can find more information on thermometric sodium determination in foods in our application video available on YouTube:https://youtu.be/lnCp9jBxoEs
- AN-H-125Determination of sodium in soy milk
This application note describes the determination of the total sodium content in soy milk products. The methodology may also be applied to the determination of sodium in milk products from cows, goats and sheep. A standard addition technique is employed to permit the accurate and precise determination of sodium at relatively low levels.
- AN-H-133Automatic sodium determination in cheese
Sodium can be determined thermometrically in cheese without sample preparation and addition of additives. A homogenizer is responsible for distribution and stirring. In addition to this application note, you can find more information on thermometric sodium determination in foods in our application video available on YouTube:https://youtu.be/lnCp9jBxoEs
- AN-H-147Potassium in fertilizers – Rapid and reliable determination by thermometric titration
Potassium is a primary macronutrient for plants, as it plays an important role in water regulation as well as plant growth. In NPK fertilizers, potassium is present besides nitrogen and phosphorus, which are the other two primary macronutrients. Knowing the quality and content of a NPK fertilizer allows an optimal fertilizer management for a planned culture, saving costs and increasing profitability.Traditionally potassium is determined gravimetrically or by flame photometry. In this Application Note, an alternative method is presented, where potassium is determined a precipitation titration. Various solid and liquid NPK fertilizers with potassium contents between 10 and 27% were analyzed. After the removal of any present ammonia, the potassium can be determined reliably in about 5 minutes.
- AN-H-148Potassium in potash
Potash is commonly mined from ore, deposited after ancient inland oceans evaporated. The potassium salt is then purified in evaporation ponds. At the end of this process, the potash is typically obtained as potassium chloride. Potash is mainly used as fertilizer, providing potassium—an essential nutrient—to plants. Additionally, it is used in the chemical industry and to produce medicine. Potassium content in potash is typically determined by flame photometry (F-AES) or ICP-OES. However, these techniques have high investment and running costs. By applying the historically used gravimetric precipitation reaction as a thermometric titration, it becomes possible to rapidly and inexpensively determine the potassium content in potash within minutes.
- AN-I-016Potassium in fruit juice and wine – Fast and economical determination by ion measurement
Determination of the potassium content plays a major role in the food and beverage industry. Potassium is an essential mineral nutrient for humans. It is an important intracellular cation and also plays an important role in processes withincells, where it is involved in the regulation of numerous body functions like blood pressure, cell growth and muscle control.To declare the potassium content of drinks and food, it is usually determined by flame photometric method. However, flame photometry is linear only over a limited concentration range, and often sample dilution is necessary. Furthermore, the instrumentation is rather complex and expensive to buy and maintain. The ion measurement method presented here is a fast, less expensive, and reliable alternative to determine potassium content in beverages.
- AN-I-017Potassium in electrolyte powder – Fast and economical determination by standard addition
The determination of the potassium content in foodstuffs plays a major role in the food and dietary supplement industry, as potassium is an essential mineral nutrient for humans. It is an important intracellular cation and also plays a important role in processes within cells, where it is involved in the regulation of numerous body functions like blood pressure, cell growth and muscle control.As a dietary supplement, potassium is present in e.g., electrolyte powder, electrolyte drinks and food supplements. To quantify the potassium content in such products, e.g. flame photometry can be used. In this work, an alternative, ion measurement by standard addition, is described, which is fast, inexpensive and simple to use.
- AN-I-022Potassium in surface water – Fast and inexpensive determination by direct measurement
Potassium is naturally occurring in surface water caused by weathering of stones and soil. As potassium in drinking water is regulated and should not exceed a certain threshold value, it is necessary to assess the potassium concentration.This can easily be done by direct measurement using a potassium selective electrode. First, a calibration is performed, afterwards, the samples are measured within tens of seconds. This is a fast, inexpensive and reliable method to determine the potassium content in various water samples.
- AN-I-035Sodium content in food using an ion-selective electrode
Excess sodium intake increases the risk of health issues. Ion-selective electrodes (ISEs) offer a fast, accurate, and cost-effective method for measuring sodium in food.
- AN-I-036Sodium content in water using an ion-selective electrode
Groundwater contains many minerals, but can be contaminated by sodium-rich leachate from landfills. Accurate Na determination in water is possible following AOAC 976.25 using the Na-ISE.
- AN-N-064Sodium dodecylsulfate (SDS) in water
Determination of sodium dodecylsulfate (SDS, sodium laurylsulfate) using anion chromatography with direct conductivity detection.
- AN-PAN-1018Online analysis of acids, bases, and aluminum in anodizing baths
Anodizing metal surfaces improves resistance against corrosion and wear. Etching baths can be monitored precisely online with the 2060 TI Process Analyzer or 2026 HD Titrolyzer.
- AN-PAN-1034Analysis of Bayer aluminate liquors using thermometric titration
The Bayer Process is the method used to refine alumina from bauxite ore, as smelting aluminum directly from alumina is much more cost- and energy-effective. In this process, "aluminate liquors" are created by digesting the crushed bauxite with CaO and NaOH at high temperatures. Additionally, the CaO causticizes carbonate which forms in the alkaline solution from organic degradation and CO2 absorption from the atmosphere. Contaminations are removed at various steps in the process, and the liquor is filtered from the alumina crystals before it is recycled back to the digestion step. Before the spent liquor can be reused, a determination of the concentrations of the total hydroxyl (“caustic”), carbonate, and alumina values is required. These parameters can be determined quickly via thermometric titration with the 2035 Process Analyzer.
- AN-PAN-1043Online trace analysis of cations in the primary circuit of nuclear power plants
In power plants, corrosion is the primary factor leading to costly and critical downtimes. In a nuclear power plant, a separate water circuit known as the Pressurized Water Reactor (PWR) ensures radioactive material stays contained while still transferring heat and energy to the other circuits. Boric acid and lithium hydroxide are added specially to the PWR circuit in amounts which can complicate other analytical measurements. Lithium prevents corrosion and must be monitored, along with other cations such as zinc, nickel, and ammonium. In order to measure these cations online at sub-µg/L range in a single analysis, the 2060 IC Process Analyzer is offered with combined Inline Preconcentration and Inline Matrix Elimination. Several cations can be analyzed in a single injection, with automated sample preparation making precise and reliable measurements easier.
- AN-PAN-1056Online monitoring of sodium in industrial power plants
In power plants, corrosion is the greatest enemy. If corrosive impurities are present in the circuit streams (e.g., chlorides and hydroxides), deposition of an insulating layer of scale on the heat transfer surfaces occurs, resulting in costly and critical downtimes. To ensure high throughput of power plants, online analysis of critical parameters such as sodium is highly advantageous for safety, protection, and process optimization. With the 2035 Process Analyzer from Metrohm Process Analytics, operators gain the information they need to accurately identify trends, reduce downtimes, and address operational issues before costly problems arise.
- AN-PAN-1058Online determination of lithium in brine streams with ion chromatography
Lithium is a soft alkali metal that is typically obtained from salt lake brines. Lithium is used for many applications, but especially for production of lithium-ion batteries in electric cars, mobile phones, and more. This Process Application Note presents a method to monitor lithium as well as other cations in brines by online process ion chromatography (IC), a multiparameter analytical technique that can measure ionic analytes in a wide range of concentrations.
- AN-Q-004Online analysis of trace cations in power plant water matrices
A setup that allows online sampling is crucial for immediate and contamination-free analysis of power plant water samples. This application recommends a setup that facilitates simultaneous anion/cation determinations. Automated inline sample preparation combines variable preconcentration (MiPCT) and calibration with a single multi-ion standard. AN-Q-005 shows the respective anion results.
- AN-S-301Comprehensive water analysis with VoltIC pro I
VoltIC pro I is the perfect combination of voltammetry and ion chromatography for the fully automated analysis of anions, cations, and heavy metals (e.g., Zn, Cd, Pb, Cu): comprehensive water analysis on a single system.
- AN-S-347Comprehensive water analysis with VoltIC Professional 1
VoltIC Professional 1 is the perfect combination of voltammetry and ion chromatography for the fully automated, simultaneous analysis of anions, cations, and heavy metals (e.g., Zn, Cd, Pb, Cu). The multiple-parameter analysis uses the same "Liquid Handling" elements and a shared sample changer, thus saving on space and costs.
- AN-S-382Metrohm IC Driver for OpenLab CDS: Anion and cation analysis in a soft drink
OpenLab CDS is the newest generation of chromatography data systems from Agilent, combining chromatography and mass spectrometry in a single software platform. The Metrohm IC Driver for OpenLab CDS integrates Metrohm IC instrumentation for full control and data acquisition. The present application describes the simultaneous analysis of anions and cations in a soft drink with a dual channel IC system. Eluent is prepared by applying Inline Eluent Production.
- AN-S-387Comprehensive water analysis with TitrIC flex II
The TitrIC flex II system is the perfect combination of titration, direct measurement, and ion chromatography for fully automated analysis of all key parameters. These include pH, conductivity, hardness, anions, cations, as well as the calculation of the ion balance: comprehensive water analysis from one system.
- AN-T-039Free alkali in sodium hypochlorite
Determination of free alkali in sodium hypochlorite by potentiometric titration with hydrochloric acid using a combined glass electrode.
- AN-T-181Lithium in brine
Lithium is a soft metal which is used for many applications, such as production of high-temperature lubricants or heat-resistant glass. Furthermore, lithium is used in large quantities in for battery production. It is obtained from brines and high-grade lithium ores. Depending on the lithium concentration, extraction may or may not be economically viable.This Application Note demonstrates a method to determine the lithium concentration in brines by potentiometric titration. Lithium and fluoride precipitate in ethanol as insoluble lithium fluoride. Using ammonium fluoride as the titrant and a fluoride ion-selective electrode (ISE), determination via potentiometric titration is possible. This method is more reliable, faster, and less expensive than the determination of lithium in brine by other more sophisticated techniques such as atomic absorption spectroscopy (AAS).
- AN-T-215Assay of lithium hydroxide and lithium carbonate
Lithium salts (e.g., lithium carbonate and lithium hydroxide) are used in myriad applications. Lithium hydroxide is used for the production of lithium stearate, an important engine lubricant. In addition, it is utilized as an air purifier due to its ability to bind carbon dioxide. While the majority of lithium carbonate is used for aluminum production, it is also used for the glass and ceramic industry. It lowers the melting point of these materials, lowering the associated electricity costs and making it cheaper to produce them.For all of these applications, it is important to know the quality of the pure lithium salts used in the various production processes. This Application Note presents an easy method for the assay of lithium hydroxide and lithium carbonate on an automated OMNIS system.
- AN-T-216Assay of lithium nitrate
Lithium nitrate is an oxidizing agent used in the manufacture of red-colored fireworks and flares. In addition, the lithium nitrate trihydrate compound absorbs heat well and can be used for thermal energy storage. Since lithium nitrate is a hygroscopic substance, its purity must first be verified before it is used for synthesis or other applications. The purity assay is done by a fully automated precipitation titration between lithium and fluoride in an ethanolic solution. The benefit of titration is that the lithium nitrate does not need to be diluted after dissolving in ethanol as with other techniques such as ICP-MS.
- EB-003Ion chromatography for food and beverage analysis
Efficiently analyze food products with ion chromatography (IC). Discover its robust applications in quality control for beverages, food additives, and dairy.
- TA-054Online monitoring of atmospheric inorganic gases and aerosols in the Southeast and Northwest of the United States
This article describes the composition of atmospheric inorganic gases and aerosols in the Southeast and Northwest of the United States during a time period of several weeks. The semicontinuous sampling in hourly cycles takes place using the MARGA system from Metrohm Applikon. The temporal resolution of the aerosol and gas composition makes it possible to generate statements regarding the chemical origin and hygroscopicity of the particles. These are fundamental for rating the influence of aerosols on the climate.
- WP-027Smart Acquire – Automated Raman Material ID for Defense and Security Professionals
An analytic chemist in your back pocket. A forensic laboratory in a suitcase. A HazMat team in the trunk of your car. First responders need all the help they can get when faced with potentially dangerous substances. Mira DS from Metrohm Raman is a sophisticated chemical analyzer that replaces the specialist with automation. The push of a button initiates proprietary Smart Acquire routines to optimize acquisition parameters and collect the highest quality spectra. These spectra are automatically subjected to library search and Mixture Matching routines capable of identifying up to three components of a mixture. When hazardous substances are detected, the user is alerted to immediate action with color-coded warnings.
- WP-028Safety in Any Situation – Addressing the needs of first responders
Metrohm Raman presents a unique handheld materials identification system designed to meet the needs of defense and security professionals. Meet Mira DS, the most adaptable Raman analyzer available today. Mira DS was developed directly in response to requests from first responders in the field for a small, rugged, automated materialsidentification system that ensures the safety of the user in any situation.
- WP-052A Guide to Li-ion Battery Research and Development
The commercialization of Li-ion batteries in 1991 was the culmination of in-depth R&D conducted by scientists and engineers around the globe over the preceding few decades. Further development of Li-ion batteries and alternative rechargeable batteries has continued until today. As the world is rapidly moving towards a new era defined by green technologies, more practical and accurate R&D is required in order to meet the increasing demands for energy storage systems, specifically from the automotive industry. This white paper presents the basics of the Li-ion battery technology and guides the reader through the relevant techniques and terminologies in Li-ion battery research.
- WP-063Recommendations for converting a manual titration procedure into an automated titration procedure
This white paper summarizes the steps involved in converting an existing manual titration procedure to semi-automated or automated titration procedures. It discusses topics such as selecting the right electrode and titration mode. For a better understanding, the discussion topics are illustrated with three examples.
- WP-066An introduction to ion chromatography mass spectrometry (IC-MS)
Ion chromatography mass spectrometry (IC-MS) is a powerful tool that can handle many challenging analytical tasks which cannot be performed adequately by IC alone. IC-MS is a robust, sensitive, and selective technique used for the determination of polar contaminants like inorganic anions, organic acids, haloacetic acids, oxyhalides, or alkali and alkaline earth metals. After separation of the sample components via IC, mass selective detection guarantees peak identity with low detection limits. The inclusion of automated Metrohm Inline Sample Preparation (MISP) allows not only water samples, but also chemicals, organic solvents, or post-explosion residues to be readily analyzed without need for extensive manual laboratory work. This White Paper explains the benefits of IC-MS over IC in certain cases, the hyphenation of IC and different MS systems, as well as related norms and standards.
- WP-068Recommendations for titration methods validation
The objective of validation of an analytical procedure is to demonstrate that it is suitable for its intended purpose. Recommendations for the validation of analytical methods can be found in ICH Guidance Q2(R1) Validation of Analytical Procedures: Text and Methodology and in USP General Chapter <1225> Validation of Compendial Procedures. The goal of this white paper is to provide some recommendations for the validation of titration methods.
- WP-070On-site Identification of Improvised Incendiary Devices: Integrated Chemical ID and Decision Guidance with MIRA DS and HazMasterG3®
Handheld Raman is ever evolving. The combination of large libraries, a compact and easy-to-use system, and predictive Hazmat software make MIRA DS a powerful tool for defense and security professionals. Identify on-site materials, get hazard information, and make quick decisions about response to dangerous situations.
- WP-077Robust multiparameter analysis of infant and follow-on formulas with ion chromatography (IC)
Free white paper gives comprehensive overview of how to reliably assess the quality of infant formula with ion chromatography.
- WP-096Validation of ion chromatographic (IC) methods according to USP <1225>
This White Paper discusses USP <1225> and how ion chromatography determines active ingredients in pharma products (assays) as well as identifies impurities and degradation components.
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