Application of Amine and Phosphotungstic Acid Groups as a Novel Bifunctional Fiber Coating in SPME-HPLC of Volatile Phenols in Water

The utilization of a bifunctional amine and H3PW12O40 (PW12) as a direct solid-phase microextraction (D-SPME) coating was investigated for the first time. The fiber was synthesized using positively charged 3-aminopropyltriethoxysilane as the crosslinking agent, and provided sites for the immobilization of PW12. Fourier transform infrared spectroscopy and field emission scanning electron microscopy were used to characterize the synthetic compound. This new fiber was developed to determine some chlorophenols [4-chlorophenol (4-CPh), 2,3-dichlorophenol (2,3-DCPh), and 2,4,6-trichlorophenol (2,4,6-TCPh)] via SPME-HPLC. Using the experimental design method, the adsorption and desorption factors of the fiber-including ionic strength and adsorption and desorption times-for the three chlorophenols were systematically investigated by SPME-HPLC-UV. In the concentration range 50-5000 mu g L-1, the calibration curves were linear for the analytes and the limits of detection varied from 0.3 to 2.5 mu g L-1. The single-fiber repeatability and fiber-to-fiber reproducibility were in the ranges 4.8-6.4 and 10.2-12.1%, respectively. The application of the fiber to environmental water samples spiked at 70 mu g L-1 with the chlorophenols yielded recoveries in the range 88.80-92.88%. Advantages of this novel bifunctional-coated SPME fiber include its increased extraction efficiency for chlorophenols and its long lifetime (it was used for > 70 cycles of D-SPME-HPLC operation without showing any appreciable reduction in extraction performance).