Purification and enrichment of polycyclic aromatic hydrocarbons in environmental water samples by column clean-up coupled with continuous flow single drop microextraction

A novel method for the determination of sixteen polycyclic aromatic hydrocarbons (PAHs) in environmental water samples was developed using column clean-up (CCU) coupled with continuous flow single drop microextraction (CF-SDME) prior to the determination by gas chromatography-mass spectrometry (GC-MS). In this method, purification, extraction and enrichment were carried out in a single step, which reduced the effect of most organic interferents on the determination of target analytes, greatly simplified the operation process and shortened the whole pre-treatment time. The CCU-CF-SDME system was first used, and shortcomings such as long extraction time, instability of suspended microdrop of the traditional SDME system were overcome. The influences of several experimental parameters, including the type and amount of column packing material, the type and volume of extraction solvent, the flow rate of sample solution, extraction temperature, pH and ionic strength of sample solution, on the extraction efficiency were investigated. Under the optimal experimental conditions, the good linearities were obtained in the concentration range of 0.02-10 μg L−1 with correlation coefficients ranging from 0.9912 to 0.9995 for all the analytes. The limits of detection and quantification of the analytes were in the range of 0.0012-0.0101 μg L−1 and 0.0041-0.0336 μg L−1, respectively. The pre-concentration factors in the range of 777-978 for the PAHs were obtained. The proposed method was applied on the analysis of environmental water samples, and the recoveries of target analytes were in the range of 81.8-105.8% with the relative standard deviations ranging from 0.5% to 6.4%. The results showed that the developed method was a simple, quick and feasible method for the determination of PAHs in environmental water samples.