Sensitive Mercury Speciation Analysis in Water by High-Performance Liquid Chromatography-Atomic Fluorescence Spectrometry Coupling with Solid-Phase Extraction

An efficient method based on high-performance liquid chromatography coupled with atomic fluorescence spectrometry (HPLC-AFS) was successfully developed for the simultaneous determination of four mercury species including Hg2+, methylmercury (MeHg), ethylmercury (EtHg), and phenylmercury (PhHg) in water. Samples were enriched and cleaned up with a solid-phase extraction (SPE) pretreatment using a thiol cartridge. Some key parameters including the selection of a SPE cartridge, eluent type, eluent volume, and interference factors were systematically investigated. Chromatographic separation was achieved on a C18 column using a mobile phase consisting of methanol and 60 mmol L-1 ammonium acetate with 10 mmol L-1 L-cysteine by gradient elution. Under the optimized conditions, good linearity (r >= 0.9991) was observed between 0.20 to 10.0 mu g L-1. The limits of detection were in the range of 0.001 - 0.002 mu g L-1. High recoveries (87.2 to 111%) and good reproducibility (1.1 - 6.5%) were obtained. Such a method is sensitive, selective and accurate, which can be applied to the quantification of mercury species in water samples.

Automated summary

An efficient method based on HPLC-AFS and SPE pretreatment was developed for simultaneous determination of four mercury species in water samples. The method showed good linearity, sensitivity, selectivity, with high recoveries and reproducibility. It can be applied for accurate quantification of mercury species in water samples.