固体吸附-热脱附/气相色谱-质谱法测定固定污染源废气中50种挥发性有机物

采用Tenax GR吸附-热脱附-气质联用法对固定污染源废气中50种挥发性有机物(VOCs)进行测定。结果显示,Tanax GR吸附管对于丙酮、环戊酮、2-庚酮、2-壬酮及六甲基二硅氧烷的吸附能力相对较差,但丙酮、环戊酮、2-庚酮、2-壬酮在2~30 ng范围内呈现良好的线性关系,且相关系数(R 2)>0.99,六甲基二硅氧烷在2~50 ng范围内呈现良好的线性关系,R^2=0.994,其他45种化合物在2~100 ng范围内呈现良好的线性关系,R^2>0.995。当采样体积为300 mL时,50种化合物的检出限为0.0003~0.0096 mg/m^3,测定下限为0.0011~0.0384 mg/m^3,相对标准偏差(RSD)<15.98%,加标回收率为78.15%~120.90%。该方法操作简单、灵敏度高、准确性好,能够满足固定污染源废气中痕量VOCs的快速检测。

Determination of 50 Volatile Organic Compounds in Stationary Source Emission

The determination of 50 volatile organic compounds in stationary source emission was carried out by Tenax GR thermal desorption-gas chromatography mass spectrometry method.The experimental results indicated that Tenax GR tubes has lower adsorption capacity for acetone,cyclopentanone,2-heptanone,2-nonone and hexamethyldisiloxane than other 45 VOCs,but the concertration of acetone,cyclopentanone,2-heptanone and 2-nonone was linearly in the range of 2~30 ng and the coefficionts efficiency were above 0.99,the concertration of hexamethyldisiloxane was linearly in the range of 2~50 ng and the coefficionts efficiency was 0.994,the concertration of other 45 VOCs was linearly in the range of 2~100 ng and the coefficionts efficiency were above 0.995.When the sampling volume was 0.3 L,the detection limit of 50 VOCs was between 0.0003~0.0096 mg/m^3 and the quantitation limit was between 0.0011~0.0384 mg/m^3,the relative standard deviations(RSD)was below 15.98% and the recoveries were between 78.15%~120.90%.The method is simple,sensitive and accurate for the detection of trace VOCs in stationary source emission.