摘要
本文采用热解吸调制器作毛细管气相色谱(GC)接顶空进样测定二元液体混合物苯-甲苯和丙酮-氯仿的活度系数.热解吸调制器是在毛细管柱前端的一段短的加热段.调制器段外部镀以一薄层导电膜.气体样品连续不断地流经调制器和毛细管柱.调制器内的.固定相瞬间地保留样品气流里的样品物.施加到导电薄膜上的电流脉冲将调制器加热,释放出的作为浓度脉冲的样品流进色谱柱.对于连续不断流动的样品气流,调制器起的作用就象自动的、高重复性的小容量注射器.用这种技术得到的短期间的相对标准偏差约为2%,该精密度比用其它技术的要好得多.
Activity coefficients of the binary liquid mixtures, benzene-toluene and acetone-chloroform were determined using thermal desorption modulation for direct headspace sampling into capillary gas chromatograph. The thermal desorption modulator is a short, heated section at the head of the capillary column. The modulator section is coated externally with a thin electrically conductive film. A gaseous headspace sample flows continuously through the modulator and the column. The stationary phase within the modulator momentarily retains sample substances from the headspace sample stream. An electrical current pulse has been applied to the electrically conductive, thin film heats the modulator section and the stationary phase within it, releasing any retained substances as a concentration pulse which flows into the following column. The modulator acts like an automatic and highly reproducible small volume injector for a continuously flowing sample stream. Short term relative standard deviations obtained using this technique are approximately 2%. This precision is better than that obtained using other techniques.
出处
《分析化学》
SCIE
EI
CAS
CSCD
北大核心
1995年第8期972-977,共6页
Chinese Journal of Analytical Chemistry
关键词
气相色谱
活度系数
二元液系
Thermal desorption modulator, headspace-capillary gas chromatography, activity coefficient
