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 Bulletin describes the complexometric potentiometric titration of metal ions. An ion-selective copper electrode is used to indicate the endpoint of the titration. Since this electrode does not respond directly to complexing agents, the corresponding Cu complex is added to the solution. With the described electrode, it is possible to determine water hardness and to analyze metal concentrations in electroplating baths, metal salts, minerals, and ores. The following metal ions have been determined: Al3+, Ba2+, Bi3+, Ca2+, Co2+, Fe3+, Mg2+, Ni2+, Pb2+, Sr2+, and Zn2+.

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.

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.