Comparison of chloride- and hydride-generation for quantitation of germanium by headspace solid-phase microextraction-inductively coupled plasma-mass spectrometry

Chloride- and hydride-generation headspace solid-phase microextraction (SPME) techniques have been compared for the detection of trace amounts of germanium by inductively coupled plasma time-of-flight mass spectrometry (ICP-TOFMS). The conditions for generation of germanium chloride, including acid type and concentration, effect of sodium chloride and extraction time, were investigated. Detection limits of 20 and 92 pg mL(-1) and precisions of 18% (n=11) and 9.7% (n=11) were achieved for chloride and hydride generation, respectively, at a concentration of 10 ng mL(-1). The generated germanium chloride and hydride species identities were characterized and confirmed as GeCl4 and GeH4 by use of electron-impact ionization mass spectrometry. Chloride generation coupled with SPME sampling and ICP-TOFMS detection resulted in twofold enhancement of sensitivity compared to GeH4 and detection limits for continuous hydride generation were 20-fold better than reported atomic fluorescence data.