Application Finder

A potentiometric method for the determination of nickel in gold and silver electroplating baths is described. The titration is carried out with KCN. Gold and silver are removed before titration by a reduction process. It is also possible to determine nickel in steel alloys, etc. (see the literature reference).Ni2+ + 4 KCN + 2NH4+ → (NH4)2[Ni(CN)4] + 4 K+

A routine method for the determination of copper is described. After dissolving the sample and adding a KI/KCNS solution, the released iodine is back-titrated with thiosulfate. The endpoint indication is potentiometric.

This Bulletin describes the simultaneous determination of gold and copper by potentiometric titration using an Fe(II) solution as titrant. Fe(II) reduces Au(III) directly to the free metal, whereas Cu(II) does not react. By the addition of fluoride ions the Fe(III) is complexed and a shift of the redox potential is effected. Afterwards, potassium iodide is added, thus reducing the Cu(II) to Cu(I), and the free iodine is again titrated with the Fe(II) solution using a Pt Titrode.Chemical reactions:Au(III) + 3 Fe(II) → Au + 3 Fe(III)2 Cu(II) + 2 I- → 2 Cu(I) + I2I2 + 2 Fe(II) → 2 I- + 2 Fe(III)

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.

The determination of cyanide is very important not only in electroplating baths and when decontaminating wastewater but, due to its high toxicity, also in water samples in general. Concentrations of 0.05 mg/L CN- can already be lethal for fish.This Bulletin describes the determination of cyanide in samples of different concentrations by potentiometric titration.Chemical reactions:2 CN- + Ag+ → [Ag(CN)2]-[Ag(CN)2]- + Ag+ → 2 AgCN

Silver is an important metal not only in jewelry and silverware but also in electrical conductors and contacts. The knowledge of the exact silver content in fine silver and silver alloys ensures that quality standards for jewelry and silverware are met. As for the plating industry, the knowledge of the amount of silver in silver plating baths helps to run the bath efficiently.While X-ray fluorescence (XRF) is a fast alternative to determine the silver content in fine silver and silver alloys, it can only determine the silver content of the outermost sections of the metal. In contrast, titration offers a more comprehensive solution considering the whole sample, thus preventing fraud by thick plating.This application bulletin describes the potentiometric determination of silver in fine silver and silver alloys accordingto EN ISO 11427, ISO 13756, GB/T 17823, and GB/T 18996 as well as in silver plating baths by a titration with potassium bromide or potassium chloride, respectively

This Application Bulletin describes the voltammetric determination of the elements antimony, bismuth, and copper. The limit of detection for the three elements is 0.5 ... 1 µg/L.

This Bulletin describes potentiometric titration methods for checking sulfuric acid and chromic acid anodizing baths. In addition to the main components aluminum, sulfuric acid, and chromic acid, chloride, oxalic acid, and sulfate are determined.

Potentiometric titration methods for the analysis of acid and alkaline tin plating baths are presented. The following methods are described: tin(II) / tin(IV) / total tin, free fluoroboric acid, or free sulfuric acid, chloride in acidic tin baths, free hydroxide, and carbonate in alkaline tin baths.

Methods are described for the potentiometric analysis of the following bath components:Brass plating bath: copper, zinc, free cyanide, ammonium, carbonate, and sulfite.Bronze plating bath: copper, tin, and free cyanide.

This Bulletin describes the potentiometric determination of lead, tin(II), and free fluoroboric acid.

This Bulletin describes titrimetric methods for the determination of cadmium, free sodium hydroxide, sodium carbonate, and total cyanide. The free cyanide can be calculated from the total cyanide and the Cd content.

This document outlines complexometric and potentiometric determination of metal ions via EDTA titration using a copper-selective electrode (Cu-ISE) with a durable epoxy shaft and crystal membrane. Because the electrode is insensitive to complexing agents, a preformed Cu–metal complex must be introduced into the sample prior to analysis. The method, applicable to direct or back-titration, exploits EDTA–metal formation constants to define equivalence points and enables quantification in several different matrices.

Potentiometric titration is an accurate method for determining chloride content. For detailed instructions and troubleshooting tips, download our Application Bulletin.

A method is described in this Bulletin that allows molybdenum to be determined in steel and other materials containing a high iron concentration. Mo(VI) is determined at the dropping mercury electrode by catalytic polarography. The determination limit is approx. 10 μg/L Mo(VI).

In most electrolytes the peak potentials of lead and tin are so close together, that a voltammetric determination is impossible. Difficulties occur especially if one of the metals is present in excess.Method 1 describes the determination of Pb and Sn. Anodic stripping voltammetry (ASV) is used under addition of cetyltrimethylammonium bromide. This method is used when:• one is mainly interested in Pb• Pb is in excess• Sn/Pb ratio is not higher than 200:1According to method 1, Sn and Pb can be determined simultaneously if the difference in the concentrations is not too high and Cd is absent.Method 2 is applied when traces of Sn and Pb are found or interfering TI and/or Cd ions are present. This method also uses DPASV in an oxalate buffer with methylene blue addition.

Thiourea forms highly insoluble compounds with mercury. The resulting anodic waves are used for the polarographic determination of thiourea. For the analysis of very small quantities (µg/L), cathodic stripping voltammetry (CSV) is used. Differential Pulse measuring mode is used in both cases.

Formaldehyde can be determined reductively at the DME. Depending on the sample composition it may be possible to determine the formaldehyde directly in the sample. If interferences occur then sample preparation may be necessary, e.g. absorption, extraction, or distillation.Two methods are described. In the first method formaldehyde is reduced directly in alkaline solution. Higher concentrations of alkaline or alkaline earth metals interfere. In such cases the second method can be applied. Formaldehyde is derivatized with hydrazine forming the hydrazone, which can be measured polarographically in acidic solution.

The Application Bulletin describes the determination of suppressor in acid copper baths by smartDT. The determination of suppressor with dilution titration (DT) involves numerous additions with standard solution or sample to reach the evaluation ratio. Usually fixed, equidistant addition volumes are used. With smartDT, variable addition volumes are used that are dynamically calculated by the software. At the beginning, the volumes are bigger. Towards the evaluation ratio, the addition volume becomes smaller to guarantee a good accuracy of the result. The operator defines the first and the smallest addition volume to be used. All volumes in between are calculated by the software considering the progress of the determination. The time saving with smartDT compared to a classic DT with fixed addition volumes can be up to 40%. smartDT is suitable for nonlinear regression and quadratic regression as well as linear interpolation. It can be used for determination of suppressor in acid copper baths as well as in tin and tin-lead baths and works with 1, 2, and 3 mm Pt working electrodes. A 800 Dosino is required for the automatic addition of suppressor standard or sample. The method can also be used in fully automated systems.

Determination of sodium hypophosphite in electroless plating solutions.

Silver and nitric acid are determined in silver electrolyte solutions by means of thermometric titration. The method provides accurate results in a short time and is ideally suited for routine process control.

Determination of fluoride in a chromium plating bath by direct potentiometry using the F-ISE.

Determination of gluconate and salicylate in a zinc plating bath using ion-exclusion chromatography with direct conductivity detection.

Determination of lactate, formate, and acetate in a cataphoretic paint bath using ion-exclusion chromatography with direct conductivity detection.

Determination of citrate, fluoride, lactate, and acetate in a plating bath using ion-exclusion chromatography with direct conductivity detection.

Determination of citric acid and lactic acid in an electroplating bath using ion-exclusion chromatography with conductivity detection.

Accurate analysis of complexing agents in galvanic baths is possible with inline Raman spectroscopy. This Application Note shows an example using a 2060 Raman Analyzer.

This Application Note explains how the 2060 XRF Process Analyzer enables real-time chemical monitoring of copper, tin, and zinc concentrations in white bronze plating baths.

The 2060 XRF Process Analyzer continuously monitors elemental concentrations online within zinc-nickel electroplating baths to precisely guide chemical dosing.

Determination of fluoride, chloride, and nitrate in a solution of NiSO4, ZnSO4 in sulfuric acid using anion chromatography with conductivity detection after chemical suppression.

Determination of chloride, sulfate, chromate, methanesulfonic acid (MSA), methanedisulfonic acid (MDSA), and ethanedisulfonic acid (EDSA) in a chromium plating bath using anion chromatography with conductivity detection after chemical suppression.

Determination of nitrate, phosphate, sulfate, and chromate in a cataphoretic paint bath using anion chromatography with conductivity detection after chemical suppression.

Determination of chloride, nitrite, nitrate, phosphate, and sulfate in an electroplating bath after inline elimination of heavy metals by cation exchange on the 793 IC Sample Prep Module using anion chromatography with conductivity detection after chemical suppression.

Determination of hypophosphite, phosphite, tartrate, tungstate, phosphate, citrate, and pyrophosphate in an electroplating bath using anion chromatography with a high pressure gradient and conductivity detection after chemical suppression.

Determination of chloride, nitrite, and sulfate in a used zinc bath using anion chromatography with conductivity detection after chemical suppression.

Determination of sulfate, molybdate, and chromate in a plating bath using anion chromatography with conductivity detection after chemical suppression.

Determination of fluoride, MSA (methylsulfonic acid), EDSA (ethyldisulfonic acid), and MDSA (methyldisulfonic acid) using anion chromatography with conductivity detection after chemical suppression.

Methanedisulfonic acid (MDSA) is used as a catalyst in chromium plating baths. The MDSA concentration in the bath must be known in order to monitor the chromating. The analysis of a bath sample requires dilution by a factor of 2,500. This Application Note shows the automatic Inline Dilution that takes place in two steps. While one sample is being analyzed, the time-optimized dilution of the next sample is already running. The MSM is regenerated using an 800 Dosino and the STREAM setup: The eluent is used for rinsing the regenerated MSM after exiting the detector.

Chrome plating is an important electroplating technique that covers metal or plastic surfaces with a thin layer of chromium for both protection and decoration purposes. The sulfate and sulfuric acid concentrations in the baths are important parameters in the coating process and require continuous monitoring. The anions in the chrome baths are separated on the Metrosep A Supp 5 - 250/4.0 column and are determined using conductivity detection in accordance with sequential suppression.

Simultaneous determination of cyanide and silver in a silver plating bath by potentiometric titration with silver nitrate using the Ag-Titrode.

Determination of Cr(VI) and Cr(III) in chromium baths by iodometric potentiometric titration with thiosulfate using the combined Pt electrode.

Determination of Sn(II) and sulfuric acid in an acidic tin plating bath by potentiometric titration.

Determination of cyanide in alkaline plating baths by potentiometric titration with silver nitrate using the Ag-Titrode.

Determination of hydroxide and carbonate in alkaline plating baths by potentiometric titration with HCl using the combined glass electrode.

Determination of cadmium, copper, lead, and zinc in alkaline plating baths by potentiometric titration with EDTA using the Cu-ISE.

Determination of palladium(II) by potentiometric titration with hexadecylpyridinium chloride using the «Ionic Surfactant» electrode.

The knowledge of the exact silver content of silver allows used for jewelry is very important to ensure the quality of jewelry. Therefore, the determination procedure is regulated internationally and nationally. A common approach is the titration with potassium bromide after an acidic digestion of the silver using a silver electrode for indication.

Electroplating processes are used in several different industry sectors to protect the surface quality of various products against corrosion or abrasion and significantly improve their working life. It is essential to check the bath composition on a regular basis to ensure that the process is operating correctly. Typical examples of electroplating baths include alkaline degreasing baths or acidic or alkaline baths containing metals e.g. copper, nickel, or chromium, or components like chloride and cyanide. It is crucial that the chosen analysis technique fulfills high safety standards for these kinds of analyses and produces reliable results. The OMNIS Sample Robot system automatically pipettes and analyzes aggressive electroplating bath samples on different workstations, increasing the safety in the lab. This provides more reliable results in comparison to manual titration and is more time efficient as different parameters can be analyzed in parallel.

Determination of Ni, Sb, Cd, Tl, and Cu in a neutral, highly concentrated zinc solution from the plating industry.

Determination of Ni, Fe, and Cu in a silver plating bath.

Determination of Cr and Se in a silver plating bath.

Determination of Sn and Pb in an organo plating bath.

Cobalt can be determined in the presence of high concentrations of gold at the DME using 5-sulfosalicylic acid as supporting electrolyte and DMG as complexing agent.

Nickel can be determined in concentrated zinc solutions by adsorptive stripping voltammetry (AdSV) at the HMDE using ammonia buffer as supporting electrolyte and dimethylglyoxime (DMG) as complexing agent. The determination of cobalt does not work under these conditions as the very high Zn2+ concentration interferes with the Co signal. Therefore, an alternative complexing agent has to be used: α-benzil dioxime in ammonia buffer under addition of sodium nitrite.

The concentration of total Sb in zinc plant electrolytes is determined by anodic stripping voltammetry (ASV) in 5 mol/L HCl. If 0.6 mol/L HCl is used, only the concentration of antimony(III) is determined selectively. The interference of an excess of Cu is suppressed by the selective oxidation of Cu. Nevertheless, the concentration of Cu in the sample limits the amount of sample that can be used for the determination.

Germanium can be determined by adsorptive stripping voltammetry (AdSV) at the HMDE using acetate buffer as supporting electrolyte and catechol as complexing agent.

Thallium and cadmium can be determined by anodic stripping voltammetry (ASV) at the HMDE (Tl) and polarography at the DME (Cd), respectively using aqueous hydrochloric acid as supporting electrolyte. Since Cd is present in high excess and would therefore interfere with the determination of thallium, a post electrolysis procedure is applied to remove the co-deposited metal from the mercury drop.

Germanium is determined by adsorptive stripping voltammetry (AdSV) at the HMDE using aqueous sulfuric acid as supporting electrolyte and pyrocatechol violet as complexing agent. It is possible to determine 20 µg/L Ge in a sample containing 150 g/L Zn, 3 g/L Cd and 1 mg/L Pb.

The concentration of Fe(total) is determined polarographically in a chromium electroplating bath. The method is suitable for iron in concentrations in the ppm range. Fe(II) and Fe(III) show signals with the same sensitivity.

Determination of suppressor «Ronastan TP Additive» in a tin/lead bath by dilution titration (DT) using cyclic voltammetric stripping (CVS).

Determination of suppressor «Solderon ST-200 Primary» in a tin bath by dilution titration (DT) using cyclic voltammetric stripping (CVS).

The concentration of Tl in a cyanidic Au bath is determined by anodic stripping voltammety (ASV) without further addition of electrolyte.

NTA in a cyanidic gold bath is determined as Bi-NTA complex by polarography. For standard addition a Bi-NTA standard solution is used.

The concentration of In in a Sn bath is determined in a HCl / Urotropin® containing electrolyte by anodic stripping voltammetry (ASV). The determination is linear up to approx. 0.5 mg/L with respect to the concentration of In in the measuring vessel. The standard addition solution is also prepared with HCl and Urotropin®.

The concentration of Bi in a Sn bath is determined in a HCl / Urotropin® containing electrolyte by anodic stripping voltammetry (ASV). A reaction time of at least 25 min is required before the determination is started. The standard addition solution is also prepared with HCl and Urotropin®.

The concentration of Se(IV) in zinc plant electrolyte is determined by cathodic stripping voltammetry (CSV) in ammonium sulfate electrolyte containing EDTA and Cu. The Cu concentration has to be adapted to the sample and the deposition time. With voltammetry only free selenium is determined, therefore it has to be taken into consideration that selenium forms sparingly soluble compounds with numerous cations (e.g. Fe2(SeO3 )3 with Ks = 2·10-31).

The concentration of Te(IV) in Zn plant electrolyte is determined by cathodic stripping voltammetry (CSV) in ammonium sulfate electrolyte containing EDTA and Cu. To get a proper complexation of the interfering Zn a high amount of EDTA is necessary at pH 3.4.

The concentration of Co in zinc plant electrolyte (neutral zinc sulfate solution) is determined by adsorptive stripping voltammetry (AdSV) in ammonia buffer with α-furildioxime as complexing agent.

The concentration of Pb in zinc sulfate solution is determined by anodic stripping voltammetry (ASV) in hydrochloric acid electrolyte.

The concentration of As(total) in zinc plant electrolyte is determined by anodic stripping voltammetry (ASV) on a lateral gold electrode in HCl electrolyte. Due to the high excess of zinc in the sample the deposition potential has to be adapted. A second potential approx. 100 mV more negative than the arsenic signal has to be applied to selectively oxidize interfering antimony. For sample preparation the sample was passed through a cation exchange column to reduce the concentration of zinc in the measuring solution.

The concentration of of Sb(III) in zinc plant electrolyte is determined by adsorptive stripping voltammetry (AdSV) with chloranilic acid as complexing agent. In this method high copper concentrations do not interfere. An approx. 10-fold excess of lead interferes, since it shows a signal close to the antimony. With the parameters given below the working range of this method is 1 - 30 µg/L antimony(III) with respect to the concentration in the measuring vessel.

Controlling Au(I) levels in gold plating baths is required for high quality. Voltammetric analysis with the Multi-Mode Electrode Pro is an efficient solution.

This Application Note describes the polarograhic determination of copper in electroplating baths used in the production of thin-film copper indium gallium diselenide solar cells (CIGS cells). The CIGS absorber layer is electrodeposited on a molybdenum-coated substrate.Copper analysis is carried out after dilution of the sample with sulfuric acid as supporting electrolyte.

This Application Note describes the polarographic determination of indium in electroplating baths used in the production of copper indium gallium diselenide thin-film solar cells (CIGS cells). The CIGS absorber layer is electrodeposited on the molybdenum-coated substrate. Indium analysis is carried out after dilution of the bath sample with sulfuric acid as supporting electrolyte.

This Application Note describes the determination of gallium in electroplating baths used in the production of copper indium gallium diselenide thin-film solar cells (CIGS cells). The CIGS absorber layer is electrodeposited on a molybdenum-coated substrate. Gallium analysis using anodic stripping voltammetry (ASV) is carried out after dilution of the sample with sulfuric acid as supporting electrolyte.

This Application Note describes the polarographic determination of selenite in electroplating baths used in the production of copper indium gallium diselenide thin-film solar cells (CIGS cells). The CIGS absorber layer is electrodeposited on a molybdenum-coated substrate. Selenite analysis is carried out after dilution of the sample with sulfuric acid as supporting electrolyte.

This Application Note describes the polarographic determination of cadmium in electroplating baths used in the production of copper indium gallium diselenide (CIGS) or copper indium diselenide thin-film solar cells (CIS). Cadmium sulfide (CdS) from the electrolyte solution is deposited as a thin film on the CIS or CIGS absorber layer via chemical bath deposition (CBD).

This Application Note describes the polarographic determination of thiourea in electroplating baths used in the production of copper indium gallium diselenide (CIGS) or copper indium diselenide thin-film solar cells (CIS). Cadmium sulfide (CdS) from the electrolyte solution is deposited as a thin film on the CIS or CIGS absorber layer via chemical bath deposition (CBD).

Ion measurement can be conducted in several different ways, e.g., ion chromatography (IC), inductively coupled plasma optical emission spectrometry (ICP-OES), or atom absorption spectroscopy (AAS). Each of these are well-established, widely used methods in analytical laboratories. However, the initial costs are relatively high. In contrast, ion measurement by the use of an ion-selective electrode (ISE) is a promising alternative to these costly techniques. This White Paper explains the challenges which may be encountered when applying standard addition or direct measurement, and how to overcome them in order for analysts to gain more confidence with this type of analysis.