Determination of H2S in Crude Oil via a Rapid, Reliable and Sensitive Method

Determination of hydrogen sulfide, (H2S) in crude oil is very important due to the environmental impacts, industrial problems and legal international limitation of transportation. In the present work, H2S of crude oil is determined by liquid-liquid extraction followed by potentiometric titration. Three factors including dilution ratio of crude oil with toluene, extraction time of H2S into the caustic phase and API of crude oil was investigated via factorial design. The ANOVA results revealed that the dilution ratio, crude type and extraction time have the highest effect of the recovery of H2S from crude oil. The linear dynamic range of the method was from  1 up to 2000 ppm which can be manipulated for lower or higher concentration by further optimization of the above-mentioned parameters. This method is rapid, reliable, operator-independent which make it a useful technique for the field test of crude oil and overcome extreme uncertainty of H2S measurement.