Determination of Total Mercury in Sediments by Microwave-assisted Digestion-Flow Injection-Inductively Coupled Plasma Mass Spectrometry

Abstract

A method for the determination of total mercury in sediment samples was developed. Extraction of mercury from a sample matrix was carried out in an open vessel microwave digestion system while maintaining mild conditions during digestion in order to avoid any loss of mercury due to volatilization. A complexing agent (EDTA) and a surfactant (Triton X-100) were added to the samples in order to eliminate memory effects associated with mercury determinations and to obtain reproducible linear calibration curves. Standard additions and internal standardization were used for calibration and correction in an FI–ICP-MS detection system. The method was validated using the certified reference material PACS-1 and the reference materials IAEA-356 and S19 and gave results in good agreement with the certified and reference values. Sediment samples from Arcachon Bay were also analysed. Detection limits of 10 ng g -1 for solution and 1 ng g -1 for dry sediment samples were obtained.