对二甲苯及其选择氧化产物的气相色谱分析

采用空气氧化法催化选择氧化对二甲苯生产对苯二甲醛是一条新的生产工艺,但对二甲苯的空气氧化产物较复杂,目前的方法难于方便、快捷地分析检测对二甲苯及其选择氧化产物对苯二甲醛。为此,以邻二氯苯为内标,建立测定对二甲苯及其选择氧化产物对苯二甲醛含量的气相色谱分析方法,结果表明:对二甲苯和对苯二甲醛在0～0.002 5 g/mL的范围内,标准工作曲线有较好的线性关系,相关系数分别为0.999 9和0.999 1。对二甲苯、对苯二甲醛回收率范围分别为100.00%～103.41%和96.80%～103.08%,标准偏差低于1.72%,变异系数低于4.80%。该方法简单便捷,分析速度快,准确度较高。

Analysis of p-xylene and its selective oxidation products by gas chromatography

Catalytic selective oxidation of p-xylene(PX) to terephthalaldehyde(TPAL) is a new production process.However,the air oxidation products of PX were complex,and it was difficult to quickly and easily analyze and detect PX and its oxidation product TPAL by the current methods.In the present study,a gas chromatographic method for determining the content of PX and its selective oxidation product TPAL was established by using 1,2-dichlorobenzene as an internal standard.The results showed that the standard curve of PX and TPAL in the range of 0~0.002 5 g/mL had good linear relations.Relative coefficients for standard curves of PX and TPAL were 0.999 9 and 0.999 1,respectively.The recovery rate of PX and TPAL were 100.00%~103.41%,96.80%~103.08%,respectively.The standard deviations of analysis for PX and TPAL were less than 1.72%,and the coefficients of variation were less than 4.80%.The present method is simple and convenient,fast,and with high accuracy.