Determination of Total Silicon in Vacuum Distillate Top Oil by Inductively Coupled Plasma Atomic Emission Spectrometry with Organic Injection

The silicon-containing compounds in the vacuum distillate top oil can clog downstream catalyst pores, causing catalyst to lose activity. However, existing methods can only detect free silicon and cannot detect volatile organic silicon, resulting in inaccurate silicon determination results. Therefore, the research mentioned by the title was conducted. The sample of the vacuum distillate top oil was mixed with aviation kerosene at mass ratio of 1∶3 for determination of the total silicon in the sample by inductively coupled plasma atomic emission spectrometry (ICP-AES) at atomization chamber temperature of -30 ℃. Organic silicon standard solutions were prepared by hexamethyldisiloxane for quantification. It was shown that linear relationship between values of the mass fraction and reponse intensity of the total silicon was kept in the range of 1.0－30.0 mg · kg⁻¹, with detection limit (3s) of 0.03 mg · kg⁻¹. Test for recovery was made according to the standard addition method, giving recoveries of total silicon in the range of 98.9%-107%, and RSDs (n=7) of the determined values were not more than 2.5%.