Polycyclic aromatic hydrocarbon purification procedures for compound specific isotope analysis.

Purification and isotope analysis methods were developed to accurately measure the stable carbon isotope ratio of individual PAHs in environmental samples. Sample extracts were separated into several fractions by column chromatography and were purified by high-performance liquid chromatographic and thin-layer chromatographic techniques. The mean recovery of the purification method for all compounds was approximately 80%. The purity of isolates was verified by GC/MS in the full scan mode. The accuracy and precision of the method were verified using authentic standards of known isotopic compositions. The standard deviation for multiple analyses ranged between 0.1 and 0.4%o for standard material and between 0.1 and 0.7%o for environmental extracts after purification. The purification and isotope analysis methods were used to discern the sources of PAHs in environmental samples using variations in stable carbon isotopic compositions of individual compounds. Itwas confirmed thatthe purification method effectively purifies environmental samples while retaining original isotopic signatures so that PAH content and stable isotopic compositions can be used to infer contaminant sources in complex environmental settings.