Determination of Inorganic Arsenic in Mineral Water and Tea Beverages by Pipette-tip Solid Phase Extraction Combined with Hydride Generation-Atomic Fluorescence Spectroscopy

Objective: Establishing a simple and convenient method for the analysis of inorganic arsenic in mineral water and tea beverages. Methods: Amino-functioned polyacrylonitrile nanofibers (NH₂-PAN nanofibers) was fabricated and used as adsorbent for pipette-tip solid-phase extraction (PT-SPE) of inorganic arsenic in mineral water and tea beverages followed by hydride generation-atomic fluorescence spectrometry (HG-AFS) analysis. Results: The optimal extraction conditions of pipette-tip solid phase extraction were that the pH of the sample solution was 8, the adsorbent was 12 mg NH₂-PAN nanofibers, and the elution solution was 5 mL HCl with a concentration of 0.01 mol/L. Under the optimum conditions, the established method showed good linearity in the range of 0.0235~60 μg/L with correlation coefficient greater than 0.994 and a precision of less than 6%. The spiked recoveries of inorganic arsenic were above 85% for both mineral water and tea beverages at two levels of spiked concentrations. Conclusion: The established NH₂-PAN nanofibers based PT-SPE/HG-AFS method is simple, accurate and expected to provide a prospective solution for the detection of inorganic arsenic.