Fabrication and application of zinc–zinc oxide nanosheets coating on an etched stainless steel wire as a selective solid-phase microextraction fiber

• Zn–ZnO coating was directly fabricated on an etched stainless steel wire substrates.
• The Zn–ZnO nanosheets coating has flower-like nanostructure with high surface area.
• The fiber has high extraction capability and good selectivity for some ultraviolet filters.
• The fabrication of Zn–ZnO nanosheets coating is simple, convenient and reproducible.
• The proposed method was suitable for the concentration and determination of target UV filters in environmental water samples.

A novel zinc–zinc oxide (Zn–ZnO) nanosheets coating was directly fabricated on an etched stainless steel wire substrate as solid-phase microextraction (SPME) fiber via previous electrodeposition of robust Zn coating. The scanning electron micrograph of the Zn–ZnO nanosheets coated fiber exhibits a flower-like nanostructure with high surface area. The SPME performance of as-fabricated fiber was investigated for the concentration and determination of polycyclic aromatic hydrocarbons, phthalates and ultraviolet (UV) filters coupled to high performance liquid chromatography with UV detection (HPLC-UV). It was found that the Zn–ZnO nanosheets coating exhibited high extraction capability, good selectivity and rapid mass transfer for some UV filters. The main parameters affecting extraction performance were investigated and optimized. Under the optimized conditions, the calibration graphs were linear over the range of 0.1–200 μg L−1. The limits of detection of the proposed method were 0.052–0.084 μg L−1 (S/N = 3). The single fiber repeatability varied from 5.18% to 7.56% and the fiber-to-fiber reproducibility ranged from 6.74% to 8.83% for the extraction of spiked water with 50 μg L−1 UV filters (n = 5). The established SPME-HPLC-UV method was successfully applied to the selective concentration and sensitive determination of target UV filters from real environmental water samples with recoveries from 85.8% to 105% at the spiking level of 10 μg L−1 and 30 μg L−1. The relative standard deviations were below 9.7%.