Determination of Methylmercury in Biological Samples Using Dithizone Extraction Method Followed by Purge & Trap GC-MS

摘要

In this study,a dithizone extraction technique involving purge & trap GC-MS was developed for the determination of methylmercury in biological samples,especially blood and fish.After alkaline digestion,methylmercury in biological samples was extracted into dithizone and back-extracted into aqueous sulfide solution.The extracted methylmercury was converted to the volatile ethyl derivative,purged and trapped onto a solid-phase collection medium,and then introduced into the GC-MS system.The determined MDLs of the established method were 0.9 ng·g~(-1) for biological samples and its accuracy and precision were found to be 93% and 3.8%,respectively.The method was validated by analysis of CRMs such as SRM 966,BCR 463 and IAEA 407 and all analytical results were within certified ranges with average RSDs of less than 6%.The analytical results of field-sampled fish also showed that the method can be successfully used as an alternative for commonly used distillation method followed by GC-CVAFS detection.