Speciation analysis of mercury in natural water and fish samples by using capillary electrophoresis–inductively coupled plasma mass spectrometry

A environment-friendly microwave-assisted extraction used to extract trace mercury compounds from fish samples, and a ultra-sensitive method for the analysis of Hg(II), methylmercury (MeHg) and ethylmercury (EtHg) by using capillary electrophoresis–inductively coupled plasma mass spectrometry (CE–ICP–MS) were described in this study. The extraction method is environment-friendly, simple, effective, and can be used to extract trace mercury compounds in fish samples with a satisfied recovery within several minutes. The CE–ICP–MS analytical method has a detection limit as lower as 0.021–0.032 ng Hg/mL for MeHg, EtHg and Hg(II), and can be used to determined ultratrace MeHg, EtHg and Hg(II) in natural water and fish samples directly without any preconcentration. With the help of the above methods, we have successfully determined MeHg, EtHg and Hg(II) in dried fish (Tapertail anchovy) muscle and natural water within 25 min with a RSD (relative standard deviation, n = 6) <5% and a recovery of 94–103%. Our results showed that dried muscle of T. anchovy contained only one species of mercury, MeHg, indicating that MeHg is easier to be accumulated by aquatic organisms.