Use of a natural sorbent as alternative solid-phase microextraction coating for the determination of polycyclic aromatic hydrocarbons in water samples by gas chromatography-mass spectrometry

Abstract

In this study, the use of bracts as a natural sorbent in solid-phase microextraction was exploited for use in the determination of polycyclic aromatic hydrocarbons in water samples with separation/detection performed by gas chromatography-mass spectrometry. Fiber-to-fiber reproducibility was evaluated and the relative standard deviation (RSD) was lower than 14%. Optimizations were performed using both the proposed and DVB/Car/PDMS (divinylbenzene/carboxen/polydimethylsiloxane) fibers. The optimum extraction conditions were 80 min of extraction at 50 °C with 12% (m/v) NaCl for the bract fiber, and 100 min of extraction at 80 °C for the commercial fiber. The limits of detection and quantification for the proposed fiber were, respectively, 0.003 and 0.01 µg L-1 for fluorene, phenanthrene, anthracene and pyrene, and 0.03 and 0.1 µg L-1 for acenaphthylene, benzo(a)anthracene and chrysene. The method using bract fiber provided relative recoveries ranging from 68 to 117%, intraday and interday precisions lower than 17 and 19%, respectively, and extraction efficiency similar to that of the DVB/Car/PDMS fiber.