Quick X-ray absorption spectroscopy for determining metal speciation in environmental samples

We present a method for determining the chemical speciation of metals in environmental particles based on Quick-X-ray Absorption Spectroscopy. The approach can be applied to either the extended or the near edge fine structure, and consists in the decomposition of the XAS spectrum of an unknown sample on a reference set of standards' spectra using quadratic linear programming. The analysis accounts for the statistical experimental errors generated during the acquisition of X-ray absorption data, and leads to error estimates on the various fractions determined via a Monte Carlo procedure. An application example is presented for the speciation of inorganic Zn in a contaminated sediment sample.