Mercury and Methylmercury in Freshwater Fish and Sediments in South Korea Using Newly Adopted Purge and Trap GC-MS Detection Method

Abstract

The use of purge and trap gas chromatography–mass spectrometry (GC-MS) technique for the determination of methylmercury in biological and sediment samples was described. The GC-MS detection system was combined with the dithizone extraction method for biological samples and the distillation method for sediment samples to alleviate matrix interference problems. The method was validated by analysis of CRMs such as SRM 966 (human blood), BCR 463 (tuna fish), IAEA 407 (fish), ERM CC580 (estuarine sediment), and IAEA 405 (sediment). The performance of the purge and trap GC-MS method was also tested on field samples of freshwater fish and sediment. The results were compared with those of the GC-ECD and the GC-CVAFS, which were used widely for methylmercury analysis. Additionally, total mercury and methylmercury levels in freshwater fish and sediments from various reservoirs and streams in Korea were measured to understand mercury contamination status in Korean peninsula. Methylmercury concentrations in freshwater fish were found to correlate with body weight, diet habit, and food availability. In sediment, total mercury concentrations correlated with methylmercury concentrations and organic matter such as %C and %S. However, no significant relationships between methylmercury and sediment organic matter have been found.