Fig. 3.

Linear combination least-squares fitting analysis of the near-edge spectra of whale skeletal muscle. The Hg L_III near-edge spectrum is fitted by a single component of methylmercury L-cysteineate, while three components are needed for the selenium K near-edge spectrum. Individual components are shown; selenocysteinate (----), selenomethionine (—) and the selenylsulfide Cys-S-Se-Cys (–.–). In both Hg and Se plots the lower traces show the fit residual plus a zero line, and these have has been vertically displaced for clarity.