亚甲蓝法在测定原油硫化氢含量中的应用

将硫化氢用不含氧的氮气从已知量的原油中吹出，用醋酸锌溶液吸收，随后在有氯化铁存在的强酸性溶液中与N,N-二甲基-1,4苯二胺反应生成亚甲蓝，用分光光度计测定亚甲蓝含量，计算得到硫化氢含量。该方法的RSD为1.3%，原油中硫化氢的加标回收率为90%?110%，检出限为0.042 μg/g。适用于原油及馏分油中硫化氢含量的测定。

DETERMINATION OF HYDROGEN SULFIDE CONTENT IN CRUDE OIL BY METHYLENE BLUE METHOD

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.