FLUORINATION ASSISTED ELECTROTHERMAL VAPORIZATION INDUCTIVELY-COUPLEDPLASMA-ATOMIC EMISSION-SPECTROMETRY - AN EFFECTIVE METHOD FOR DIRECT DETERMINATION OF REFRACTORY ELEMENTS IN SOLID BIOLOGICAL SAMPLES

A new method for direct ICP-AES determination of refractory elements i n solid biological materials with slurry sampling electrothermal vapor ization (ETV) for sample introduction is described. A polytetrafluoroe thylene (PTFE) slurry is used as fluorinating reagent to promote the v aporization of refractory elements from the graphite furnace. The fluo rinating vaporization of refractory elements, the matrix effects, and the particle size effects have been investigated systematically. The d etection limits of this method for determination of refractory element s boron, molybdenum, chromium, and lanthanum are 24, 7.0, 14, and 60 p g, respectively; the RSD are in the range of 2.4-3.8% The proposed met hod has been applied to determine trace boron, molybdenum, chromium, a nd lanthanum in standard biological reference materials, and the deter mined values are in good agreement with the certified values. (C) 1996 Academic Press, Inc.