TiO2 nanotube array micro-solid phase equilibrium extraction for the determination of bisphenol A, 4-n-nonylphenol, and 4-tert-octylphenol at trace levels with high-performance liquid chromatography

Abstract

This paper reports on research to establish a micro-solid phase equilibrium extraction using a highly ordered titanium dioxide (TiO₂) nanotube array for the pre-concentration and determination of environmental endocrine disruptors. The analysis was performed using high-performance liquid chromatography (HPLC) with fluorescence and ultraviolet detection. The experimental results showed that method detection limits (MDL) with fluorescence detection were 0.012, 0.033, 0.036 μg L⁻¹ and MDL with ultraviolet detection were 0.022, 0.049, 0.093 μg L⁻¹ for bisphenol A, 4-tert-octylphenol and 4-n-nonylphenol, respectively. The proposed method was successfully applied to the analysis of the target compounds in several environmental water samples. Good spiked recoveries in the range of 75.4–103.4% and 74.8–106.2% were obtained by using HPLC with fluorescence and ultraviolet detectors, respectively. These results showed that TiO₂ nanotube arrays would be useful in the enrichment and determination of trace pollutants.