AEROSOL DEPOSITION DIRECT SAMPLE INSERTION FOR ULTRA-TRACE ELEMENTAL ANALYSIS BY INDUCTIVELY-COUPLED PLASMA-MASS SPECTROMETRY

Analysis Direct deposition of a liquid sample as an aerosol into an in ductively heated graphite direct sample insertion probe is described a s a means of preconcentration and high efficiency sample introduction for ICP-MS. A two minute deposition at 0.25 ml min(-1) resulted in 3s detection limits ranging from 0.06 to 1.8 pg ml(-1) (0.03-0.9 pg) for the eight elements studied, These limits represent an element specific improvement averaging two orders of magnitude over the nebulizer/spra y chamber-based sample introduction detection limits on the same instr ument, The effect of varying several parameters related to the ICP and the deposition process was investigated, The performance of the syste m with samples in an ethanol matrix was also demonstrated, The deposit ion and insertion procedure was automated, providing RSDs of approxima tely 5% at the 1 ng ml(-1) level. Analytical accuracy was assessed by replicate measurements of a Riverine Water Reference Material for Trac e Metals (SLRS-2, National Research Council of Canada). Good agreement between calculated and certified values was obtained.