INDUCTIVELY HEATED VAPORIZER FOR INDUCTIVELY-COUPLED PLASMA-MASS SPECTROMETRY

An inductively heated vaporizer (MV) was used to introduce analyte, as a dry aerosol, into an ICP MS instrument. Sample volumes of 5-300 mu l were pipetted into a graphite cup, which was then placed in the indu ction coil of the IHV to dry, pyrolyze and vaporize the analytes of in terest. A small amount of N-2, added to the Ar carrier flow, was used to prevent arcing between the graphite cup and the induction coil of t he induction furnace, Experimental parameters such as Ar carrier flow, rf power and torch position were optimized by placing a small crystal of I-2 in the graphite cup of the IHV and maximizing the I-127(+) sig nal. Linearity of the calibration graphs improved and integrated signa l intensity increased with increased mass of analyte deposited in the graphite cup. Limits of detection (LODs) in the range 3-100 pg ml(-1) were achieved for Ag, Ph, Cd, Tl and Zn. When compared with solution n ebulization, these LODs represent an improvement of 3- to 30-fold depe nding on the element.