Rapid Determination of Hydrogen Sulfide in Crude Oil and Fuel Oil by Electrochemical Sensor Method with Liquid Phase Extraction

For crude oil or fuel oil samples that could flow freely at room temperature, the sample was taken directly by injector. For crude oil or fuel oil samples that couldn't flow freely at room temperature, the sample was taken after being heated to flow (temperature was no more than 40 ℃) in a water bath under airtight condition, or after being stirred violently. The taken sample was diluted with class Ⅱ base oil, and hydrogen sulfide in the sample was extracted by air bubble extraction. Mercaptan and thioether in the air flow were adsorbed by the adsorbent.Electrochemical sensor method was applied to the rapid determination of hydrogen sulfide in the air flow. Linearity range of hydrogen sulfide was found in the range within 200.0 mg·kg^-1 with detection limit (3s) of 0.02 mg·kg^-1. On the base of blank sample of crude oil, test for recovery was made by standard addition method; values of recovery found were in the range of 98.9%-100%, with RSDs (n=6) of determined values in the range of 0.30%-2.3%.