Determination of Arsenic Species in Edible Mushrooms by High-Performance Liquid Chromatography Coupled to Inductively Coupled Plasma Mass Spectrometry

Abstract

The content of total arsenic was determined by inductively coupled plasma mass spectrometry after microwave digestion. The results showed that the content of total arsenic was ranged from 0.04 to 212.3 mg kg−1 in the test edible mushrooms. The content of total arsenic in eight test samples was greater than 0.5 mg kg−1. However, the toxicity of arsenic is closely related to the chemical form. Therefore, the determination of arsenobetaine, arsenocholine, dimethylarsinic acid, monomethylarsonic acid, arsenite, and arsenate in edible mushrooms was performed on an ion exchange chromatography column (Dionex IonPac AS19) with inductively coupled plasma mass spectrometry as a detector. When water and 50 mM (NH4)2CO3 (pH = 9.7) were worked as a mobile phase, the six arsenic species could be well separated in 20 min. Ultrapure water was selected as extraction solvent for the validation of ultrasound-assisted extraction method due to its advantage of simple, cheap, and high extraction efficiency. Under optimum conditions, the limits of detection were 91.0 % with the relative standard deviation of <5.5 %. The method was applied to 19 different mushroom samples. The results indicated that the total content of arsenic species was basically identical with the content of total arsenic. And arsenobetaine was proved to be the main arsenic species in the test Lentinus edodes-2 sample.