mixing ammonium thiocyanate to concentrated sulfuric acid and adding water to it.

Biosynthesis

Hydrogen sulfide can be generated in cells via enzymatic or non-enzymatic pathways. Three enzymes catalyze formation of : cystathionine ?-lyase (CSE), cystathionine ?-synthetase (CBS), and 3-mercaptopyruvate sulfurtransferase (3-MST). CBS and CSE are the main proponents