Direct Determination of Ultraviolet Filters in Environmental Water Samples using Solid-phase Microextraction with Functionalized Gold Nanoparticles Coating

Abstract

A novel functionalized solid-phase microextraction (SPME) fiber coating was prepared by simple and rapid self-assembling technique between the fiber surface gold nanoparticles (AuNPs) and 11-mercapto-1-undecanol (HO-C11-SH) using an etched stainless steel wire (ESSW) as a supporting substrate. The ESSW offers a rough surface structure and very large contact surface for subsequent electrochemical deposition of AuNPs in chloroauric acid solution. As a result, uniform AuNPs coating was tightly attached to the ESSW substrate, which was used as an alternative substrate for self-assembly of HS-C11-OH via Au-S bonding. The 11-mercapto-1-undecanol modified AuNPs coated ESSW (HO-C11-S-AuNPs/ESSW) fiber was assessed for SPME of ultraviolet filters coupled to high-performance liquid chromatography with UV detection. The fabricated fiber exhibited good extraction performance for four kinds of organic UV filters in environmental water samples. The main parameters affecting extraction performance were investigated and optimized for SPME performance of UV filters. Under the optimized conditions, a good linearity was obtained between 0.10 and 400 μg L–1 with correlation coefficients in the range of 0.9940–0.9982. The limits of detection ranged from 0.024 to 0.081 μg L–1. The single fiber repeatability varied from 5.7 to 7.6% and the fiber-to-fiber reproducibility of five fabricated fibers ranged from 7.6 to 9.1% for the extraction of spiked water with 100 μg L−1 UV filters. The SPME-HPLC-UV method was established for the selective preconcentration and determination of trace ultraviolet (UV) filters from environmental water samples. Furthermore, the fabricated HO-C11-S-AuNPs/ESSW fiber has high stability and long lifetime, and good extraction capability for UV filters compared to the commercially available fiber.