近红外光谱法快速测定汽油中含苯体积分数
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摘要
根据SH/T 0713—2002测定了131个汽油样品[随机抽取92~#(95~#)车用汽油、92~#(95~#)车用乙醇汽油调和组分油,装置馏出口S-Zorb汽油、石脑油和重整汽油,以及后三者配制的调和汽油]的含苯体积分数。以此为基准,在近红外光谱图中,基线和光程分别在7 529～8 994,7 560～8 940 cm~(-1)中校正,当模型的主因子数为8个,建模区间为6 048～6 210 cm~(-1)时,利用光谱计量学建模软件,采用偏最小二乘法建立了汽油含苯体积分数近红外定量分析模型:y=0.994 346 40 x+0.003 730 98。结果表明:采用该模型预测汽油中含苯体积分数的重复性指标远低于SH/T 0713—2002要求,预测值平均正确率高达95.7%;预测所需时间仅为2 min,低于采用后者所需的20 min;该模型可以取代SH/T 0713—2002用作汽油含苯体积分数的预测。
The volume fractions of benzene were determined by SH/T 0713—2002 in the 131 gasoline samples [randomly selected 92~#(95~#) motor gasoline, 92~#(95~#) vehicle ethanol gasoline blending component, equipment distillation outlet S-Zorb gasoline, naphtha and reformed gasoline, and the latter three blended gasoline].On this basis, in the near-infrared spectroscopy, under the conditions of baseline and optical path correction ranges 7 529-8 994,7 560-8 940 cm~(-1) respectively,principal factors of the model 8, and modeling interval 6 048-6 210 cm~(-1),the near-infrared quantitative analysis model for the volume fraction of benzene in gasoline was established by the partial least squares method with the spectral metrology modeling software: y=0.994 346 40 x+0.003 730 98.The results showed that the repeatability index of this model to predict the volume fraction of benzene in gasoline was much lower than the repeatability requirement of SH/T 0713—2002, the average correct rate of prediction was more than 95.7%; the prediction time was only 2 min, shorter than that of the latter 20 min required for the determination.Therefore,this model could replaceSH/T 0713—2002 for predicting the volume fraction of benzene in gasoline.
The volume fractions of benzene were determined by SH/T 0713—2002 in the 131 gasoline samples [randomly selected 92~#(95~#) motor gasoline, 92~#(95~#) vehicle ethanol gasoline blending component, equipment distillation outlet S-Zorb gasoline, naphtha and reformed gasoline, and the latter three blended gasoline].On this basis, in the near-infrared spectroscopy, under the conditions of baseline and optical path correction ranges 7 529-8 994,7 560-8 940 cm~(-1) respectively,principal factors of the model 8, and modeling interval 6 048-6 210 cm~(-1),the near-infrared quantitative analysis model for the volume fraction of benzene in gasoline was established by the partial least squares method with the spectral metrology modeling software: y=0.994 346 40 x+0.003 730 98.The results showed that the repeatability index of this model to predict the volume fraction of benzene in gasoline was much lower than the repeatability requirement of SH/T 0713—2002, the average correct rate of prediction was more than 95.7%; the prediction time was only 2 min, shorter than that of the latter 20 min required for the determination.Therefore,this model could replaceSH/T 0713—2002 for predicting the volume fraction of benzene in gasoline.
引文
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[3]韦树琛,丁欣,李文霞,等.废旧聚酯纤维制品近红外定量分析模型的建立及验证[J].纺织学报,2018,39(7):66.
[2]陆婉珍,袁宏福,徐广通,等.现代近红外光谱分析技术[M].北京:中国石化出版社,2000:30-31.
[3]韦树琛,丁欣,李文霞,等.废旧聚酯纤维制品近红外定量分析模型的建立及验证[J].纺织学报,2018,39(7):66.