Analysis of Four Arsenic Species in Different Types of Rice Based on Liquid Chromatography-Atomic Fluorescence Spectrometry

Abstract

A fast analytical protocol for the simultaneous analysis of As(Ⅲ), As(Ⅴ), DMA and MMA in purple rice, red rice and common brown rice was established based on liquid chromatography-atomic fluorescence spectrometry. For the first time, three mobile phases (i.e. KH2PO4, (NH4)2CO3 and NH4HCO3) were examined to obtain separation conditions. The results showed that NH4HCO3 is the most effective eluent achieving the separation of As species with improved resolutions within 10 minutes. Bond elut carbon bulk, bond elut carbon and C18 were compared in view of their purification and adsorption capacities. The results showed that the C18 column can fully remove the pigment and macromolecular impurities. Four arsenic species had good linearity in the concentration ranging from 0 to 50 μg/L, and the correlation coefficients were all greater than 0.999 1. The limits of detection and the limits of quantification of the method were 0.002~0.01 mg/kg and 0.007~0.033 mg/kg, respectively. The recoveries of the four arsenic species at three spike levels in three rice matrices ranging from 75.2% to 104%, with the relative standard deviations is less than 9.9%. It is suitable for the analysis of the content of 4 arsenic species in various types of rice, and provides reliable technical support for accurately assessing the risk of arsenic intake in rice.

Keywords

• rice
• arsenic species
• purification
• liquid chromatography-atomic fluorescence spectrometry