US FDA: Elemental Analysis Manual: Section 4.11: Arsenic Speciation in Rice and Rice Products Using HPLC-ICP-MS
The method provides a procedure for arsenic speciation analysis of rice and rice-containing food products including white and brown rice, rice breakfast cereals, rice crackers, rice cakes, and rice beverages. The method utilizes high performance liquid chromatography coupled to inductively coupled plasma mass spectrometry (HPLC-ICP-MS) to determine inorganic arsenic (iAs) as the sum of two inorganic forms of arsenic, arsenite (As(III)) and arsenate (As(V)). Additionally, monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA) are determined. Concentrations of individual arsenic species determined in samples are reported based on elemental arsenic concentrations (i.e., µg of As per kg food). Other matrices may be analyzed by this procedure if performance is verified in the matrix of interest and at the analyte(s) concentration of interest.