Determination of Trace Arsenic Content in Commercial Crispbread by Hydride Generation Inductively Coupled Plasma Optical Emission Spectrometry

Abstract

Methodology for the determination of total As in crispbread by hydride generation inductively coupled plasma optical emission spectrometry (HG–ICP–OES) was evaluated. The effect of pre-reduction reagents before the HG reaction under conditions of real samples was investigated. Sonication (15 min, 25°C) of samples with aqua regia allowed complete release of As species in solutions. Arsenic hydride was generated in the reaction with NaBH4 (1.0 % (m/v)) after the pre-reduction of AsV to AsIII with ascorbic acid (1.5 % (m/v)) and KI (0.5 % (m/v)) in 3 mol L–1 HCl. Detection limits (LODs) of 0.46 (AsIII) and 0.49 (AsV) μg L–1 were assessed. The accuracy of the method was confirmed by analysis with a certificate reference material and recovery test. Various crispbreads (wheat, rye, corn, rice) were analysed with the developed procedure and As content varied between 0.027 and 0.219 μg g–1, being the highest in the rice samples.