Abstract: Hydrogen sulfide (H2S) levels in plasma are useful in diagnosing cardiovascular disease. The ratio of H2S to NO in plasma is useful in diagnosing peripheral artery disease.

Abstract: A method to measure all relevant biologic hydrogen sulfide pools, namely free hydrogen sulfide, acid-labile sulfide, and bound sulfane sulfur, has been developed. This new method involves selective liberation, trapping and derivatization of labile hydrogen sulfide. The total labile sulfide, including the contribution of the bound sulfane sulfur pool, the acid-labile pool, and free H2S, was measured by incubating the sample with a reducing agent, TCEP (Tris(2-carboxyethyl)phosphine hydrochloride), to reduce disulfide bonds in an acid solution. This method was used to measure the three sulfide pools in blood samples from mice and from humans. This method can be used for research, environmental, and clinical diagnostic purposes in determining hydrogen sulfide bioavailability in biological or other samples.