Sulfur speciation in soil by S K-Edge XANES spectroscopy: comparison of spectral deconvolution and linear combination fitting.

Defined, quartz-diluted mixtures of sulfur (S) compounds with different oxidation state (OS) were analyzed by K-edge XANES spectroscopy using linear combination fitting (LCF) and spectrum deconvolution by fitting several Gaussian and arctangent functions (GCF). Additionally, for different soils the S speciation as calculated by both methods was compared with results of a wet-chemical S speciation. For mixtures of FeS, L-cysteine, and Na2SO4, the S speciation was recovered with satisfactory accuracy and precision by both methods at the 2 and 0.