吹扫捕集-气相色谱法测定海水中苯、甲苯、乙苯和二甲苯的生物降解

Determination of Biodegradation Products from Benzene, Toluene, Ethylbenzene and Xylenes in Seawater by Purge and Trap Gas Chromatography

苯、甲苯、乙苯和二甲苯（简称BTEX）等单环芳烃是石油的重要组分.在油气地球化学勘查领域,BTEX是油气藏信息的直接指示物.BTEX具有挥发性,并且可以受到微生物的降解作用,直接影响到BTEX含量的准确测量.本研究建立了动态顶空（吹扫捕集）和光离子化检测器（PID）的气相色谱测量海水基样品中BTEX的生物降解方法.苯、甲苯、乙苯、对间二甲苯及邻二甲苯的检出限分别为7.3、8.1、11.4、8.3、13.2 ng/L;1 μg/L海水样品中BTEX回收率为92.84%～ 100.92%.样品无需预处理.BTEX生物降解规律对海洋油气地球化学勘探中所涉及的样品采集、运输、保存、测量及结果分析具有重要指导意义.

Benzene, toluene, ethylbenzene and xylenes（BTEX） are commonly found in crud oil and used as the directing referent in the geochemical investigation for oil and gas. BTEX are easily volatile and can be degradated by microorganism, which affect the precision measurement seriously. A method for the determinatron of biodegradation products for BTEX in seawater is described. Determination is performed by dynamic headspace （purge and trap ） gas chromatography with photoionization detection （PID）. The features of the described method are detection limits of 7.3 - 13.2 ng/L, no sample preparation and the recovery rate of 92. 84% - 100. 92%. The results of BTEX biodegradation are of great significance in tile collection, transportation, preservation and measurement of samples in the geochemical investigation for oil and gas.