An analyzer is described for the detn. of S in org. and inorg. compds. The S-contg. compds. are reduced to H2S by HI, HCl, and NaH2PO2 at 135 Deg. The H2S gas is transferred into a H diffusion flame by an auxilliary gas (Ar or N). H2S forms S2 mols. in the flame. The chemiluminescence of this reaction is measured at 350-410 nm.