Q: Which voltammetric instruments support mercury-free electrodes?

The 884 Professional VA and 946 Portable VA Analyzer both support mercury-free electrodes. With the 884 Professional VA , it is possible to work with a number of different electrodes. Historically, the Multi Mode Electrode Pro (Hg-drop electrode) was used for voltammetric analysis. Now, many determinations can be performed with solid electrodes like gold, bismuth, and glassy carbon. Screen-printed electrodes can also be used. The 884 Professional VA has an exchangeable measuring head which allows the same instrument to be used easily with multiple electrode types and for different types of analysis without any risk of cross-contamination. If you are interested in performing field-based measurements and need a portable instrument, the 946 Portable VA Analyzer is the best choice. This convienent and compact instrument is ready to go with you to perform on-site analysis of heavy metals in water, using our scTRACE Gold electrodes or screen-printed electrodes.

Question 1

Can I use CVS to control organic additives in electroplating?

Accepted Answer

CVS (Cyclic Voltammetric Stripping) analysis is the standard technique used in the copper plating industry to determine the concentration of organic additives in the acid copper plating bath. This method is recommended by plating bath suppliers and is used in various industries including PCB manufacturing, semiconductor packaging, copper foil manufacturing, and more.

The term «CVS» covers several applications including the determination of suppressors, brighteners, and levelers. These additives are essential for achieving uniformity, smoothness, and optimal thickness of deposited copper.

Blog: Introduction to Cyclic Voltammetric Stripping (CVS)

Question 2

Which applications can I perform with a voltammetric analyzer?

Accepted Answer

A voltammetric analyzer is used to quantify trace levels of electro-active species in various matrices.

Some of the most common applications are:

Heavy metals in water (drinking water, environmental samples, sea water)
Various additives and impurities in chemicals and electroplating baths
Anions and impurities in chemical feedstocks

Learn more in our application documents

Question 3

Can CVS measure low concentrations of additives accurately?

Accepted Answer

Yes, CVS can measure low concentrations of additives accurately.

Depending on the chemistry of the plating bath, additives may be present in various concentrations. CVS can be applied to determine the relevant additives and concentration ranges. The parameters of the CVS measurement are optimized for the chemistry of the plating bath, ensuring the most accurate results for each situation.

See Metrohm's solution: the Professional CVS

Question 4

Does the voltammetric instrument setup support automatic sample changers?

Accepted Answer

Yes. It is very common to run voltammetric analysis on automated sample series. The perfect set up for automated voltammetric analysis is the MVA-22 configuration.

This system handles automated determinations for sample series of up to 28 samples, along with automated rinsing of the analysis vessel.

Go to 884 Professional VA system with automation

Question 5

What is the best analytical technique for measuring trace levels of heavy metals in water?

Accepted Answer

There are several options available for measuring trace levels of metals in water and other matrices, including atomic absorption spectrometry (AAS), inductively coupled plasma mass spectrometry (ICP-MS), and voltammetry (VA). Each technique has advantages and limitations, therefore selecting a technique depends strongly on the details of the sample and the analysis requirements. Briefly, here are some situations where VA may be the best choice:

Samples with high salt content, such as sea water and brine. The presence of salts in the matrix is generally no problem for voltammetric analysis, but it usually complicates ICP-MS measurements.

White paper: Green alternative methods for voltammetric analysis in different water matrices

Application Note: Cadmium and lead in drinking water with a Bi drop electrode

Application Note: Cadmium, lead, and copper in brine and sodium hydroxide

Application Bulletin: Determination of zinc, cadmium, lead, copper, thallium, nickel and cobalt in water samples by anodic and adsorptive stripping voltammetry according to DIN 38406-16

Situations where portability (946 Portable VA Analyzer) is necessary, or laboratory space is limited, since VA analyzers are relatively small (the 884 Professional VA is roughly the size of your kitchen microwave) and portable options for field measurements are available.

When speciation is important, voltammetric analysis can be the ideal solution. Since VA measures the electrochemical signal produced when the ion interacts with the electrode, it is often possible to distinguish between the various oxidation states of the analyte. Examples includeArsenic, Selenium, Tin, Iron.

Question 6

What is the best voltammetry system for trace metal detection?

Accepted Answer

The best voltammetry system for trace metal detection offers several features including:

support a variety of measurement techniques like differential pulse voltammetry, square wave voltammetry, cyclic voltammetry, and more
support a variety of calibration techniques
offer a user-friendly software that takes care of analysis, volume book-keeping, automation, and reporting
offer the possibility to automate the determination
be flexible to support a variety of applications and allow the use of different working electrodes such as the Mercury drop electrode, solid-state electrodes, rotating electrodes, and screen-printed electrodes.

See Metrohm's solution: the 884 Professional VA

Question 7

Why is CVS used for electroplating bath analysis?

Accepted Answer

With CVS, the concentration of additives like suppressors, brighteners, and levelers can be accurately determined. CVS is especially interesting because it measures the concentration of the additives using their electrochemical behavior in conditions that are very similar to their function in the plating bath. This makes the CVS technique perfectly-suited for this type of analysis.

CVS is used to analyze the concentration of various additives in electroplating baths. It is most widely used in acid copper electroplatings baths.

Blog: Introduction to Cyclic Voltammetric Stripping (CVS)

CVS is used to analyze the concentration of various additives in electroplating baths. It is most widely used in acid copper electroplatings baths.

Blog: Introduction to Cyclic Voltammetric Stripping (CVS)

Question 8

Which voltammetric instruments support mercury-free electrodes?

Accepted Answer

The 884 Professional VA and 946 Portable VA Analyzer both support mercury-free electrodes.

With the 884 Professional VA, it is possible to work with a number of different electrodes.

Historically, the Multi Mode Electrode Pro (Hg-drop electrode) was used for voltammetric analysis. Now, many determinations can be performed with solid electrodes like gold, bismuth, and glassy carbon. Screen-printed electrodes can also be used.

The 884 Professional VA has an exchangeable measuring head which allows the same instrument to be used easily with multiple electrode types and for different types of analysis without any risk of cross-contamination.

If you are interested in performing field-based measurements and need a portable instrument, the 946 Portable VA Analyzer is the best choice. This convienent and compact instrument is ready to go with you to perform on-site analysis of heavy metals in water, using our scTRACE Gold electrodes or screen-printed electrodes.

Question 9

Which instrument should I use for heavy metal analysis in water?

Accepted Answer

The 884 Professional VA with the viva software is ideal for heavy metal analysis in water.

With this instrument, you can use a variety of techniques, different working electrodes, and you can chose your level of automation. The viva software makes analysis of measuring curves and further calculations fast and easy.

Learn more about the 884 Professional VA

Question 10

How do I make CVS analysis more accurate?

Accepted Answer

CVS is generally considered the best way to measure the concentration of organic additives in acid copper plating baths. The quality of CVS results can be verified using best practices such as running check standard measurements, and performing adequate conditioning, cleaning, and maintenance of the analytical equipment.

For our best advice on how to perform high-quality CVS measurements, please consult our Daily Routine document

Cycling Voltammetric Stripping: Daily routine for best performance (PDF, 1.63 MB)

Implementing automation can be a great step, not only to increase sample throughput and efficiency in the laboratory, but to increase the quality of the measurement. By implementing automated sample dosing and addition of auxiliary solution and standards, the possibility of pipetting errors is eliminated.