有机进样-电感耦合等离子体原子发射光谱法测定减顶油中总硅的含量

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

减顶油中的含硅化合物会堵塞下游催化剂孔洞导致催化剂失去活性,而现有方法只能检测游离硅,不能检测挥发性有机硅,造成硅测定结果不准确,因此进行了题示研究。将减顶油样品和航空煤油以质量比1∶3混合,在-30℃雾化室温度下用电感耦合等离子体原子发射光谱法(ICP-AES)测定样品中的总硅,以六甲基二硅氧烷配制有机硅标准溶液进行定量。结果显示:总硅的质量分数在1.0~30.0 mg·kg^(−1)内和对应的响应强度呈线性关系,检出限(3s)为0.03 mg·kg^(−1);按照标准加入法进行回收试验,总硅的回收率为98.9%~107%,测定值的相对标准偏差(n=7)不大于2.5%。

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%.