热脱附——气相色谱/质谱联用测定室内空气中苯系物的方法探讨

A Study of Determination Method for Benzene Homologues in Indoor Air by means of Automated Thermal Desorber-Gas Chromatography/Mass Spectrometry

[目的]建立用热脱附-气相色谱/质谱联用法(ATD-GC/MS)测定室内空气中苯系物的分析方法。[方法]采用TenaxTA吸附-二次热解吸-毛细管气相色谱/质谱法定量,研究确定了采样方法、解吸条件和分析条件。[结果]实验表明苯、甲苯、乙苯、间(对)二甲苯、苯乙烯和邻二甲苯的吸附效率均在97%以上,解吸效率均在99%以上,其相对标准偏差小于10%,回收率在96.8%～104.8%之间,线性相关系数在0.9993～0.9997之间,对应的最低检出浓度分别为0.0001、0.0007、0.0005、0.0005、0.0005、0.0007mg/m^3。[结论]本方法适合测定室内空气中低浓度的苯系物。

[Objective]To establish an analytical method to determine benzene homologues in indoor air by means of ATD-GC/MS,a physical way. [Methods]The research determines the sampling methods,the desorption conditions and the analytical conditions by means of Tenax TA adsorption-thermal desorption-capillary gas chromatography/mass. [Results]The results of experiments show that the adsorption efficiency of benzene,toluene,ethyl-benzene m(p)-xylene,phenethyl and o-xylene is all higher than 97% while desorption efficiency all above 99%.The relative standard deviations (RSDs) are less than 10%.The recoveries of them ranged from 96.8% to 104.8% while the linear correlation coefficient ranges from 0.9993 to 0.9997.The limit of determination for benzene,toluene,ethyl-benzene,m(p)-xylene,phenethyl and o-xylene is 0.0001,0.0007,0.0005,0.0005, 0.0005,0.0007 mg/m^3 respectively. [Conclusion]The method is suitable for the determination of low-concentration benzene homologues in indoor air.