Determination of methylmercury and ethylmercury in aquatic products by microwave -assisted extraction coupled with high performance liquid chromatography-inductively coupled plamas mass spectrometry

A high performance microwave-assisted extraction-high performance liquid chromatography-inductively coupled plamas mass spectrometry （HPLC-ICP/MS）method was developed for determination of methylmercury and ethylmercury in aquatic products. In this experiment, methylmercury and ethylmercury were extract from the aquatic products with microwave assisted, and 5 mol/L hydrochloric acid solution used as extraction solvent. 8% (V/V) methanol aqueous solution containing 0.12% (V/V) L- cysteine and 0.01mol/L ammonium acetate buffer were used as mobile phase. The quantitative analysis of target compounds was carried out by HPLC-ICP/ MS within 5 minutes. Under the optimized conditions, the detection limit of methylmercury and ethylmercury were up to 0.024 μg/L and 0.042 μg/L, there were good linear relationships in the 0.05~20 μg/L for methylmercury and ethylmercury, and the correlation coefficients were 0.9999. The average spiked recoveries ranged from 84.0% to 94.5%. The relative standard deviations of intra-batch and inter-batch were in the range of 2.1%~4.1% and 2.6%~4.3%, respectively. This method was simple, rapid, sensetive and accutate, meet the mercury speciation quantitative requirements.