TiO2-coated Hollow Fiber Microextraction Combined with Electrothermal Vaporization-Inductively Coupled Plasma-Mass Spectrometry for Trace Elements Analysis in Environmental Water Samples
Abstract TiO2 coated hollow fiber (HF) was prepared by sol-gel method and characterized by X-ray powder diffraction and scanning electron microscope. The adsorption performance of the self-prepared TiO2 coated HF for interest metal ions was explored and a series of affecting factors including sample pH, extraction time, stirring rate and desorption condition were investigated and optimized. On basis of this, a method combining TiO2 coated HF micro-solid phase extraction with electrothermal vaporization (ETV)-inductively coupled plasma mass spectrometry (ICP-MS) was developed for the determination of trace metal ions in environmental water samples. Under the optimized conditions, the limits of detection obtained by the proposed method were 0.039, 0.021, 0.009 and 0.018 ng mL−1 for Cr(III), Cu(II), Cd(II) and Pb(II) with enrichment factors of 12.5, 11.7, 10.3 and 18.6, respectively. The preparation reproducibility of self-prepared TiO2 coated HF ranged from 4.5% to 6.8% (n = 9) in one batch, and from 7.7% to 9.6% (n = 7) in batch-to-batch. The developed method was validated by analyzing a certified reference material (GSBZ50009-88 200925) and also applied to the analysis of target metal ions in East Lake water and snow water successfully. Meanwhile, TiO2 coated HF stir bar was prepared for a comparison and it was demonstrated that TiO2 coated HF displayed higher extraction efficiency and adsorption capacity for the target ions.