GC-ECD DETERMINATION OF METHYLMERCURY IN SEDIMENT SAMPLES USING A SPB-608 CAPILLARY COLUMN AFTER ALKALINE DIGESTION

The determination of methylmercury in sediment by gas chromatography w ith electron capture detector is proposed. Performance of a 0.53 mu m i.d. capillary column SPB-608 has been evaluated. A procedure of extra ction of methylmercury from sediment, based on an alkaline digestion ( KOH/CH3OH) in ultrasonic bath followed by organic solvent extraction a nd cleanup step, has been optimized. Various alkaline and acid treatme nts as well as different digestion times have been tested. The perform ance of the method has been tested by participating in intercomparison and certification exercises for methylmercury in sediment organized b y the Standards, Measurements, and Testing Programme of the European U nion and by using an International Atomic Energy Agency certified refe rence sediment for methylmercury. (C) 1997 Academic Press.