Mercury speciation in seafood samples by LC–ICP-MS with a rapid ultrasound-assisted extraction procedure: Application to the determination of mercury in Brazilian seafood samples

Abstract

This paper describes a simple method for mercury speciation in seafood samples by LC–ICP-MS with a fast sample preparation procedure. Prior to analysis, mercury species were extracted from food samples with a solution containing mercaptoethanol, l-cysteine and HCl and sonication for 15min. Separation of mercury species was accomplished in less than 5min on a C8 reverse phase column with a mobile phase containing 0.05%-v/v mercaptoethanol, 0.4%m/v l-cysteine and 0.06molL−1 ammonium acetate. The method detection limits were found to be 0.25, 0.20 and 0.1ngg−1 for inorganic mercury, ethylmercury and methylmercury, respectively. Method accuracy is traceable to Certified Reference Materials (DOLT-3 and DORM-3) from the National Research Council Canada (NRCC). With the proposed method there is a considerable reduction of the time of sample preparation. Finally, the method was applied for the speciation of mercury in seafood samples purchased from the Brazilian market.