Sulfur and amorphous dithiazine measurement

A method of producing oil, said method comprising:

• a) obtaining a plurality of samples, each sample from a known location in an oil reservoir and containing MEA or a triazine, or MEA or a triazine being added thereto;
• b) optionally analyzing each of said plurality of samples or portion thereof to determine a first amount of H2S remaining unreacted with said MEA or triazine after step a);
• c) analyzing each of said plurality of samples or portion thereof to determine an amount of dithiazine and correlating said amount of dithiazine to a second amount of H2S;
• d) analyzing each of said plurality of samples or portion thereof for an amount of amorphous dithiazine (a-DTZ) by treatment with a reductive mercaptan solution to convert a-DZT to H2S and measuring a third amount of H2S and correlating said third amount of H2S to said amount of a-DTZ in said plurality of samples;
• e) calculating a total amount of H2S in a each sample from a each said known location by adding said optional first amount of H2S from step b), said second amount of H2S from step c), and said third amount of H2S from step d), thereby determining one or more highest H2S content location(s) in said reservoir and one or more sweeter content location(s);
• f) producing oil from said one or more sweeter content location(s) as determined in step e);
• and
• g) wherein said produced oil has less H2S than a method of producing oil from said reservoir without steps a) through f).