National Research Council of Canada. NRC Institute for National Measurement Standards
A low power atmospheric pressure plasma source, furnace atomization plasma emission spectrometry (FAPES), was directly coupled to both a conventional chemical vapor generation system based on use of tin chloride reductant as well as a UV-photoreduction system for detection of cold vapor mercury. The resonance line emission at 253.7 nm was monitored. The 70 W low power He plasma was tolerant to the introduction of water vapor from the gas–liquid separator and, with the furnace heated to 400 °C, a precision of measurement of 2.4% RSD at 1 ng mL−1 was achieved. A limit of detection of 250 pg mL−1Hg in river water samples via UV-photoreduction and 240 pg mL−1 using conventional tin chloride reduction was obtained. The LOD could be improved 5-fold through use of a simple gold amalgamation system. Conventional chemical generation of mercury using the NaBH4/HCl system produced too much hydrogen to permit efficient coupling to the FAPES source as the He plasma is extinguished by the load of molecular vapor (i.e., hydrogen).
Journal of Analytical Atomic Spectrometry24 (11 February 2009): 689–694.