N,N-Dimethyl-1,4-phenylene diamine reacts with hydrogen sulphide to form an unstable compound which rearranges to leucomethylene blue. Oxidation with iron(III) ions yields methylene blue.

In water sulphides can be present as dissolved hydrogen sulphide or as hydrosulphide or sulphide ions.

N,N-Dimethyl-1,4-phenylene diamine reacts with hydrogen sulphide to form an unstable compound which rearranges to leucomethylene blue. Oxidation with iron(III) ions yields methylene blue.

In water sulphides can be present as dissolved hydrogen sulphide or as hydrosulphide or sulphide ions.

N,N-Dimethyl-1,4-phenylene diamine reacts with hydrogen sulphide to form an unstable compound which rearranges to leucomethylene blue. Oxidation with iron(III) ions yields methylene blue.

In water sulphides can be present as dissolved hydrogen sulphide or as hydrosulphide or sulphide ions.