【摘要】 采用微流路控制Deans Switch中心切割技术和双氢火焰离子化检测器,建立了测定乙苯中微量二甲苯含量的方法。该方法采用两根不同长度的FFAP色谱柱,使除对、间二甲苯外的其他烃类杂质在长60m的FFAP毛细管柱1上与乙苯峰分离,当绝大部分乙苯从色谱柱1流出后,改变载气的流动方向,将未分离的少量乙苯连同对、间二甲苯一起采用中心切割的方式切换至长30m的FFAP色谱柱2上进一步分离,测定其含量。对、间、邻二甲苯的检测限分别为1.7,1.4,1.4μg/g。采用外标法定量时,二甲苯的回收率为95.2%～110.0%。采用内标法定量和两次进样,该方法除可测定乙苯中微量二甲苯的含量外,还可按SH/T1148—2001《工业用乙苯纯度及烃类杂质的测定气相色谱法》测定乙苯中其他微量烃类杂质的含量。更多还原

【Abstract】 An analytical method for determination of trace xylenes in ethylbenzene was established by means of microfluid heart-cut(Deans Switch) two dimensional GC system with two flame ionization detectors.A 60 m FFAP column 1 was used to separate most of the impurities except p/m-xylenes from ethylbenzene.After main part of ethylbenzene was eluted from the column 1,the flow direction of carrier gas was changed and p/m-xylenes with a little of unseparated ethylbenzene were cut to another 30 m FFAP column 2 for further separation and determination.The detection limits for p-,m-,and o-xylenes were 1.7,1.4,1.4 μg/g respectively.By adoption of external standard quantitative method,the recoveries of the determination were 95.2%-110.0%.By adoption of internal standard quantitative method and twice injections of samples,other impurities in ethylbenzene could be detected according to SH/T 1148—2001.更多还原