This document specifies a method for the determination of alkylmercury compounds in filtered water samples by gas chromatography-mass spectrometry after phenylation and solvent extraction.

This method is applicable to determination of individual methylmercury (MeHg) and ethylmercury (EtHg) compounds in surface water and waste water.

The method can be applied to samples containing 0,2 μg/l to 10 μg/l of each compound as mercury mass. Depending on the matrix, the method may also be applicable to higher concentrations after suitable dilution of the sample or reduction in sample size.