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目的建立居住区大气中苯、甲苯和二甲苯测定的气相色谱标准方法。方法空气中苯、甲苯和二甲苯用活性炭管采集,经二硫化碳解吸后,毛细管色谱柱分离,氢火焰离子化检测器检测,以保留时间定性,峰面积定量。结果进样1μl时,苯、甲苯、对二甲苯、间二甲苯和邻二甲苯检出限分别为:1.9×10-4μg、2.2×10~(-4)μg、3.0×10~(-4)μg、3.0×10~(-4)μg和3.7×10-4μg;当使用活性炭管采样20 L,用1 ml二硫化碳解吸样品时,苯、甲苯、对二甲苯、间二甲苯和邻二甲苯的测定范围分别为0.031 mg/m~3~20.0 mg/m~3、0.036 mg/m~3~20.0 mg/m~3、0.050 mg/m~3~20.0 mg/m~3、0.050 mg/m~3~20.0 mg/m~3、0.060 mg/m~3~20.0 mg/m~3;重复测定的相对标准偏差(RSD)为0.19%~1.4%。3个浓度水平的加标回收率在94.0%~99.0%范围内。结论本方法适用于居住区大气中苯、甲苯和二甲苯浓度的测定。也适用于室内空气中苯、甲苯和二甲苯浓度的测定。
Objective To establish a standard method for the determination of benzene, toluene and xylene in the residential area by gas chromatography. Methods The benzene, toluene and xylene in the air were collected by activated charcoal tube, desorbed by carbon disulfide, separated by capillary column and detected by hydrogen flame ionization detector. The retention time was qualitative and the peak area was quantified. Results The detection limits of benzene, toluene, p-xylene, m-xylene and o-xylene were 1.9 × 10-4μg, 2.2 × 10-4μg, 3.0 × 10-4 ) μg, 3.0 × 10 ~ (-4) μg and 3.7 × 10-4μg, respectively. When 20 L of activated charcoal tube was used for sample desorption with 1 ml of carbon disulfide, benzene, toluene, paraxylene, metaxylene and orthoxylene The determination ranges were 0.031 mg / m ~ 3 ~ 20.0 mg / m ~ 3,0.036 mg / m ~ 3 ~ 20.0 mg / m ~ 3,0.050 mg / m ~ 3 ~ 20.0 mg / m ~ 3,0.050 mg / m ~ 3 ~ 20.0 mg / m ~ 3 and 0.060 mg / m ~ 3 ~ 20.0 mg / m ~ 3 respectively. The relative standard deviations (RSDs) of repeated measurements were 0.19% ~ 1.4%. The spiked recoveries of three concentration levels ranged from 94.0% to 99.0%. Conclusion This method is suitable for the determination of benzene, toluene and xylene concentrations in the atmosphere of residential areas. Also applies to the determination of benzene, toluene and xylene concentrations in indoor air.