FIG. 1.

X-ray near-edge spectroscopy (XANES) to determine sulfur composition of soil. Sulfur K-edge spectra were measured for a number of standard compounds and fitted to Gaussian curves (B). These were then used to model the XANES spectrum of the studied Danish agricultural soil (A, unbroken line), as described in Materials and Methods. The optimized model spectrum (A, dashed line) gave the sulfur species composition given in Table 5. BS, benzenesulfonate; Met-SO, methionine sulfoxide; Met-SO₂, methionine sulfone.