Determination of mercury species by the diffusive gradient in thin film technique and liquid chromatography – atomic fluorescence spectrometry after microwave extraction

• Published in: Analytica chimica acta Vol. 866; pp. 21 - 26
• Main Authors: Pelcová, Pavlína, Dočekalová, Hana, Kleckerová, Andrea
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 25-03-2015
• Subjects: Diffusive gradients in thin film technique; Liquid chromatography–cold vapor atomic fluorescence spectrometry; Mercury species; Microwave-assisted extraction; DGT; MAE; CV-AFS; Diffusive gradients in thin film technique; Mercury species; Microwave-assisted extraction; Liquid chromatography–cold vapor atomic fluorescence spectrometry
• ISSN: 0003-2670; 1873-4324
• DOI: 10.1016/j.aca.2015.01.043

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•DGT–MAE–LC–CV-AFS method was developed for determination of four mercury species.•The microwave extraction was used for isolation of mercury species from resin gels.•Optimized DGT–MAE–LC–CV-AFS method provides low detection limits (13–38ngL−1).•The diffusion coefficients of four mercury species were simultaneously determined.
A diffusive gradient in thin films technique (DGT) was combined with liquid chromatography (LC) and cold vapor atomic fluorescence spectrometry (CV-AFS) for the simultaneous quantification of four mercury species (Hg2+, CH3Hg+, C2H5Hg+, and C6H5Hg+). After diffusion through an agarose diffusive layer, the mercury species were accumulated in resin gels containing thiol-functionalized ion-exchange resins (Duolite GT73, and Ambersep GT74). A microwave-assisted extraction (MAE) in the presence of 6M HCl and 5M HCl (55°C, 15min) was used for isolation of mercury species from Ambersep and Duolite resin gels, respectively. The extraction efficiency was higher than 95.0% (RSD 3.5%). The mercury species were separated with a mobile phase containing 6.2% methanol+0.05% 2-mercaptoethanol+0.02M ammonium acetate with a stepwise increase of methanol content up to 80% in the 16th min on a Zorbax C18 reverse phase column. The LODs of DGT–MAE–LC–CV-AFS method were 38ngL−1 for CH3Hg+, 13ngL−1 for Hg2+, 34ngL−1 for C2H5Hg+ and 30ngL−1 for C6H5Hg+ for 24h DGT accumulation at 25°C.