Cold vapour generation electrothermal atomic absorption spectrometry and solid phase extraction based on a new nanosorbent for sensitive Hg determination in environmental samples (sea water and river water)

Abstract

A rapid and simple method was developed for separation and pre-concentration of mercury by flow injection solid phase extraction coupled with on-line chemical vapour generation electrothermal atomic absorption spectrometry (CV-HG ETAAS). The system is based on chelating retention of the analyte onto the mini column filled with a new nanosorbent, mesoporous silica functionalized with 1,5 bis (di-2-pyridyl) methylene thiocarbohydrazide. The main aim of this work was to develop a precise and accurate method for the determination of Hg. Under the optima conditions and 120s preconcentration time, the detection limit obtained was 0.008μgL−1, with RSDs 3.0% for 0.2μgL−1, 2.6% for 1μgL−1 and an enrichment factor of 4. Furthermore, the method proposed has permitted the determination of Hg with low consumption of reagents and a sample throughput of about 18h−1.The method was applied to the determination of Hg in sea water and river water. For the quality control of the analytical performance and the validation of the newly developed method, the analysis of two certified samples, TMDA 54.4, Fortified Lake, and LGC6187 River sediment was addressed. The results showed good agreement with the certified values.