Mechanical stir bar sorptive extraction followed by gas chromatography as a new method for determining polycyclic aromatic hydrocarbons in water samples

A new and highly sensitive analytical technique based on mechanical stir bar sorptive extraction followed by gas chromatography-flame ionization detector (MSBSE-GC-FID) for the simultaneous determination of five polycyclic aromatic hydrocarbons (PAHs) in water samples was developed. A polypyrrole-polyaniline nanocomposite conducting polymers was used as extraction phase. Experimental parameters controlling the performance of MSBSE process were optimized using response surface methodology (RSM) based on central composite design (CCD). Under optimum conditions, the calibration curves showed high levels of linearity (R2 > 0.9922) for PAHs in the range of 2-450 ng mL− 1. Limits of detection (LODs) and limits of quantification (LOQs) were 0.02-1.10 ng mL− 1 and 0.06-3.33 ng mL− 1, respectively. The relative standard deviations (RSD%) for five analyses at a concentration of 20 ng mL− 1 were less than 10%. Accuracy was calculated as the relative recoveries (recovery%) for the analysis of known amounts of target analytes added to actual water samples using the proposed method. The recoveries of those compounds in spiked water samples at a concentration of 2 μg mL− 1 were obtained from 86% to 100%. High recovery, short extraction time, ease of use, and acceptable merit figures compared to other methods are advantages of the new proposed method. The performance of the present method was evaluated for determining of PAHs in different water samples (wastewater, fountains water, and seawater) and satisfactory results were obtained.