Thiomercurimetric determination of sulphur, aliphatic and aromatic thiols and disulphides in hydrocarbon solvents, using reduction with sodium aluminium bis(2-methoxyethoxy)dihydride

A method is proposed for determination of hydrogen sulphide and aliphatic and aromatic thiols in hydrocarbon solvents by extraction with 2M potassium hydroxide and titration with o-hydroxymercuribenzoic acid in the presence of dithiofluorescein and dithizone, with selective masking with acrylonitrile. Sulphur and organic disulphides are readily converted by sodium aluminium bis(2-methoxyethoxy)dihydride in benzene solution into hydrogen sulphide and thiols, which can either be directly titrated after dilution with alcohol or separated by extraction and determined in the presence of each other.