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

Benzene, toluene, ethylbenzene and xylenes (BTEX) are commonly found in crud oil and used as the direct indicating substance in the Geochemical Investigation for Oil and Gas. BTEX are easily volatile and can be degraded by microorganism, which affects the precise measurement seriously. A method for the determination of the biodegradation process of BTEX in seawater is described. The determination is performed by dynamic headspace (purge and trap) gas chromatography with a photoionization detector (PID). The features of the described method are: detection limits of 7.3–13.2 ng l−1, no sample preparation required, and recovery rate of 92.84%–100.92%. The results of the BTEX biodegradation process are of great significance in the collection, transportation, preservation, and measurement of samples in the Geochemical Investigation for Oil and Gas.