气相色谱微体积热导检测器测量氙

气相色谱微体积热导检测器(μTCD)是与毛细管柱相连的浓度型检测器。为提高-TCD测量氙的能力,研究了色谱进样条件、分离条件和检测条件对氙响应影响。结果表明,当柱流量为1.5mL/min,1.0mL样品完全进样所需最短时间为0.4min;等量氙响应值随着柱流量的增加而增大,与色谱柱温度无关;在流量比(q)等于2.3时,等量氙响应值达到最大(0.98-V.s/hPa);且当q=2～3时,其均值为0.97-V.s/hPa;相对标准偏差(RSD)为1.2%。

Xenon Responding Analyzed by Using Micro-Thermal Conductivity Detector for Gas Chromatography

Concentration is an essential parameter for xenon monitoring in the International Monitoring System of the Comprehensive-Nuclear-Test-Ban-Treaty.Gas chromatography single resistance heating element micro-thermal conductivity detector(μTCD),concentration detector for any compound,was connected with capillary column and applied upon xenon concentration measurement.In order to improve the TCD measurements of xenon ability,the chromatography sampling conditions,separation conditions and detection conditions on xenon response were investigated,such as swept time for 1.0 mL sample in loop,column flow rate,reference flow and Make up flow rate,oven and detector temperature.In this paper equivalent xenon response value(EXRV) was particularly discussed.The results show that,when the column flow rate is 1.5 mL/min,the shortest time that complete 1.0 mL gas sample into column is 0.4 min.The EXRV increases with increasing column flow rate,and independent of oven temperature.At last,when the flow-rate ratio is equal to 2.3,EXRV reaching the maximum 0.98 μV·s/hPa,and when flow-rate ratio changes in 2-3,the mean EXRV is 0.97 μV·s/hPa,relative standard deviation is 1.2%.And so,all of flow rates of column,reference and Make up can influence the xenon′s signal apparently,we can improve the detector performance by adjusting these parameters in practice if required.