Study of Some Tungsten-Containing Chemical Modifiers in Graphite-Furnace Atomic Absorption Spectrometry

Abstract

Several chemical modifiers based on tungsten have been evaluated: the individual modifiers W(VI) as WO₃ in aq. 0.2 M NH₃ and W(V) as W in H₂O₂ and the mixed modifiers W(VI)/NH₃ + Pd(II), W(V)/H₂O₂ + Pd(II), and W(V)/H₂O₂ + PO₄ ^3-. High efficiency of thermal stabilization for 18 analyte elements of high and moderate volatility has been demonstrated and possible mechanisms of stabilization are discussed.