Mass-spectrometric determination of metal chelates

A rapid and accurate (3% rel.) mass-spectrometric determination of some poly-isotopic transition metals as their chelates with 2-thenoyltrifluoroacetone has been developed. The analysis of nanogram amounts of zinc, nickel and chromium has been accomplished using enriched stable metal isotopes as the internal standard. The mass spectra are generally well-defined and simple allowing simultaneous determinations in mixtures. The influence of other transition metals (Cu, Co, Fe and Mn) on the determination is discussed together with the analytical consequences of metal-metal chelate exchange reactions in the ion-source for determinations of iron and cobalt.