Division 2.4.6 Specific requirements for cold vapour atomic absorption spectrometry

Cold vapour is used only in the case of mercury. Due to volatilisation and adsorption losses of elemental mercury, special care is necessary during the whole analysis. Contamination by reagents or the environment has to be avoided carefully.

Organic compounds containing mercury require oxidative decomposition to obtain correct results for total mercury content. For decomposition, sealed systems with microwave digestion or high pressure asher are to be used. Special care is required for cleaning the equipment that had contact with mercury.

Working with the flow injection technique is advantageous. For lower decision limits, adsorption of elemental mercury on gold/platinum adsorber followed by thermal desorption is recommended. Contact of the adsorber or the cell with moisture will disturb the measurement and shall be avoided.