Microscale Synthesis of Fe(PF(3))(5) for Gas Source Mass Spectrometry.

Down-scaling of a cocondensation method to produce volatile pentakis(trifluorophosphine)iron(0) for measuring isotope ratios by gas source mass spectrometry is described. Starting from 10 mg of iron, this method allows synthesis of a sufficient amount of Fe(PF(3))(5) that can be used 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. Reproducibilities for n((54)Fe)/n((56)Fe) and n((57)Fe)/n((56)Fe) are (1-3) × 10(-4), while those obtained by thermal ionization mass spectrometry are at the 10(-3) level.