Fluorination assisted electrothermal vaporization inductively coupled plasma 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 in solid biological materials with slurry sampling electrothermal vaporization (ETV) for sample introduction is described. A polytetrafluoroethylene (PTFE) slurry is used as fluorinating reagent to promote the vaporization of refractory elements from the graphite furnace. The fluorinating vaporization of refractory elements, the matrix effects, and the particle size effects have been investigated systematically. The detection limits of this method for determination of refractory elements boron, molybdenum, chromium, and lanthanum are 24, 7.0, 14, and 60 pg, respectively; the RSD are in the range of 2.4-3.8% The proposed method has been applied to determine trace boron, molybdenum, chromium, and lanthanum in standard biological reference materials, and the determined values are in good agreement with the certified values. (C) 1996 Academic Press, Inc.