Optimization of the coupling of multicapillary GC with ICP-MS for mercury speciation analysis in biological materials

The coupling between multicapillary gas chromatography (MCGC) and inductive ly coupled plasma mass spectrometry (ICP-MS) was optimized with the objecti ve of minimizing the detection limits and time necessary for the species-se lective determination of mercury compounds. The most critical parameters in fluencing the sensitivity were the position of the capillary inside the ICP injector, the makeup gas flow rate and the column temperature. The interfa ce itself did not need to be heated. An absolute detection limit of 0.08 pg could be achieved and was controlled by the injection speed and the data a cquisition rate of the quadrupole mass analyser. Using a previously develop ed automated purge-and-trap accessory, a method for the analysis of fish sa mples was developed and validated by the analysis of the DORM-1 and TORT-1 National Research Council of Canada (NRCC) certified reference materials. T he experimental detection limit for methylmercury was 0.2 ng g(-1); for Hg2 + it was controlled by the reagent blank.