Get more detailed insights on how to perform salt, sodium, chloride and mineral content determinations.
In this application note, a method to determine the chloride content of an electroplating bath containing oxidative chromate and dichromate ions using the chloride-selective PerfectION comb Cl electrode is described.
Background
Titration is often the method of choice to determine the chloride content. Mohr's method uses the following chemical reaction:
Cl-(aq) + AgNO3 (aq) → AgCl (↓) + NO3- (aq)
Chloride (Cl-) is titrated with an aqueous silver nitrate (AgNO3) solution leading to the precipitation of insoluble silver chloride (AgCl). Usually, the reaction is monitored using a silver ring electrode, which is sensitive to silver ions (Ag+) At the equivalence point (EQP), the chloride ions are exhausted and the subsequently added silver ions accumulate and contribute to the measured signal. This leads to a rapid potential change.
However, for some samples the EQP cannot be detected with the silver ring electrode. The reason might be either interferences from other reductive or oxidative species or masking of the (excess) silver ions. Electroplating baths for example often contain oxidative or reductive metal ions or other compounds that react with silver ions (e.g. chromates or cyanides).
This application note includes:
- General introduction
- Sample preparation and procedures
- Solutions and chemicals
- Chemistry
- Instruments and accessories
- Method in detail
- Results and remarks
And method files (.lmt and .xml) for direct import and implementation on the instrument.
