MICROSCALE SYNTHESIS OF FE(PF3)(5) FOR GAS-SOURCE MASS-SPECTROMETRY

Down-scaling of a cocondensation method to produce volatile pentakis(t rifluorophosphine)iron(0) for measuring isotope ratios by gas source m ass spectrometry is described. Starting from 10 mg of iron, this metho d allows synthesis of a sufficient amount of Fe(PF3)(5) that can be us ed to measure iron content and/or isotope ratios in real-life samples. The advantage over thermal;ionisation mass spectrometry is that more precise determinations of ratios/amounts are possible. Reproducibiliti es for n(Fe-54)/n(Fe-56) and n(Fe-57)/n(Fe-56) are (1-3) x 10(-4), whi le those obtained by thermal ionization mass spectrometry are at the 1 0(-3) level.