Date de publication: 2021
Two approaches to Hg speciation analysis, both employing volatile species generation (VSG) were optimized and subsequently applied to biological sample analysis. The first one employs post-column VSG after HPLC separation of Hg species (Hg2+, MeHg+, EtHg+ and PhHg+) prior to their ICP-MS detection (HPLC-VSG-ICP-MS). The optimized post-column VSG step enhances sensitivity 30–40 times and improves limits of detection (LOD) by a factor of five in comparison with the setup without VSG step (HPLC-ICP-MS). LODs between 3 and 6 ng L−1 have been reached by HPLC-VCG-ICP-MS while those reached by HPLC-ICP-MS ranged significantly higher (15–26 ng L−1). Additionally, the VSG step reduces significantly the effect of organic mobile phase on ICP plasma during gradient elution required for PhHg+ determination. Moreover, a simple and short (7 min) two-stage extraction procedure was proposed for simultaneous determination of Hg2+, MeHg+ and EtHg+ in human blood. Acceptable extraction efficiency of Hg species without their inter-conversions was confirmed by Hg speciation analysis in human blood certified reference materials (Seronorm Trace Elements Whole Blood L-1 and L-2) resulting in recoveries better than 90% (Hg2+, MeHg+) and 80% for EtHg+, respectively. The second approach to Hg speciation analysis is based on selective extraction of MeHg+ from hair samples with 2 mol L−1 HCl. Extraction selectivity was verified by HPLC-ICP-MS employing the IAEA-086 certified reference material of human hair. Three spectrometric detectors were compared for subsequent Hg determination in the extracts from hair including single purpose mercury analyzer AMA-254, VSG-AAS and ICP-MS resulting in MeHg+ recovery of 100 ± 10%.
Microchemical Journal Volume 170, November 2021, 106606