Simultaneous determination and distribution analysis of eleven arsenic species in vegetables

Abstract

A highly sensitive and efficient method for simultaneous determination of arsenic species in vegetables has been developed. Eleven arsenic species were separated and detected using high performance ion exchange chromatography-inductively coupled plasma mass spectrometry (HPIEC-ICP-MS). The extraction efficiency and transformation of arsenic species in vegetables was investigated using five extraction methods and eight solvents. An online background removal technique was firstly established to exclude the influence of environmental arsenic. The gradient elution conditions were optimized and the optimal collision gas velocity for mass spectrometry was determined to be 4 mL min−1 to remove interference by 75ArCl. The detection limits for the method were 0.032–0.12 μg kg−1, and the quantitative limits of the method were 0.10–0.39 μg kg−1. In order to confirm the accuracy and practicability of the method, two food matrix-type certified reference materials were analyzed. The types and concentrations of arsenic species in six different kinds of vegetable were analyzed. The proportions of As (III) and As (V), as well as total arsenic concentrations, were significantly different.