Abstract:

Hydrogen sulfide is stripped out from a known mass of the crude oil with oxygen-free nitrogen into zinc acetate solution. The adsorbed hydrogen sulfide is subsequently reacted with N,N-dimethyl-1,4-phenylenediamine dihydrochloride in a strongly acidic solution with ferric chloride to form methylene blue. The amount of methylene blue is then determined by spectrophotometry to calculate the content of H2S. The determination limit of H2S is 0.042 ug/g，the RSD is 1.3%，and the spiked recoveries are ranged from 90% to 110%. This method can be applied to the determination of H2S in crude oil and its distillates.

Key words: hydrogen sulfide, crude oil, methylene blue method