Tenax富集—毛细管气相色谱法同时测定环境空气中12种氯苯类化合物

Simultaneous determination of trace 12 chlorinated benzene compounds in air by capillary gas chromatography with Tenax adsorption tube enrichment

建立了毛细管气相色谱法同时分离快速测定环境空气中12种氯苯类有机污染物的方法。采集10L空气样品。用Tenax吸附管富集氯苯类化合物，石油醚淋洗解析．DB．23毛细管柱分离．电子捕获检测器检测。空气中氧苯类化合物的最低检测浓度分别为：氯苯20μg／m^3。二氯苯0．5—0．8μg/m^3，三氯苯0．08—0．1μg／m^3，四氯苯0.03—0．05μg／m^3，五氯苯、六氯苯0．01μg／m^3。在空白试验中，回收率为90．7％-100．6％。相对标准偏差低于7．16％（n=5）。结果表明，该测定方法简便、快速、准确、重现性好，适合环境空气中12种氯苯类化合物的痕量测定。

The paper is to introduce a new method developed by the given authors for capillary gas chromatography determination of 12 chlorinated benzene compounds （such as chlorobenzene, diehlorobenzenes, trichlorobenzensles, etc. ） in the samples collected from the air. As a matter of fact, the chlorinated benzene compounds in the air samples here described were first of all collected by using a Tenax adsorption tube at 0.5 L/min and in 20 min, with the volume of air sample being abound 10 L. The analysis results indicate that the desorption effect of the petroleum ether （ 60 - 90 ℃ ） can be thought of to be the best of all. As chlorinated benzene compounds in the Tenax tube are concerned, they can be dissolved with 1.0 mL petroleum ether and 1.0 μL of the solution injected on a DB-23 capillary column and determined by the gas chromatography with electron capture detectors （GC-ECD）. Then the 12 kinds of benzene compounds can be separated in the said capillary column. Then, the quantitative determination can be done according to the external standards. While average recovery of the chlorinated benzene compounds （spiked at the deferent levels） ranges from 90.7% to 100.6% with the relative standard deviations being less than 7.16% （ n = 5）, the air sample volume is usually 10 L. It can also be determined that, the detected limits of chlorobenzenes and dichlorobenzenes are 20 μg/m^3 and 0.5 - 0. 8 μg/m^3, respectively, with the trichlorobenzenales being 0.08 -0. 1 μg/m^3, and the tetroehlorobenzenes-equal to 0.03 - 0.05 μg/m^3. In addition, the limits of pentachlorobenzene and hexachlorobenzene are beth 0.001 μg/m^3. From the above illustration, the method can be regarded as being simple, fast, sensitive and accurate for tracing and determining the chlorinated benzene compounds with the samples collected from the air.