Analysis of heavy metals in rice bran oil by inductively coupled plasma (ICP) spectrometry

Authors: Dunn, Robert; BAKOTA, ERICA - Harris County Institute Of Forensic Sciences; Liu, Sean

Submitted to: Annual Meeting and Expo of the American Oil Chemists' Society
Publication Type: Abstract Only
Publication Acceptance Date: 2/1/2017
Publication Date: 4/30/2017
Citation: Dunn, R.O., Bakota, E.L., Liu, S.X. 2017. Analysis of heavy metals in rice bran oil by inductively coupled plasma (ICP) spectrometry [abstract]. American Oil Chemists' Society Annual Meeting. p. 54.

Interpretive Summary:

Technical Abstract: Rice is one of the most important staple crops in the world. Nevertheless, health-conscious consumers have expressed concern regarding the presence of heavy metals, specifically arsenic, in rice. The United Nations Food and Agriculture Organization (UNFAO) limits the arsenic concentration at 0.2 mg/kg in rice, but has no set limit in rice bran oil. Rice bran oil is known to have good antioxidant activity in foods. The study evaluates the use of inductively coupled plasma (ICP) spectrometry in determining the concentration of arsenic, cadmium, lead, mercury, and zinc metals concentrations in crude and refined rice bran oils. Most analytical laboratories digest oil samples into an aqueous matrix before running the analysis for heavy metals. However, digestion or organic samples may increase the experimental error in the analysis. In the present work, the digestion step was omitted and the oil samples mixed with kerosene before ICP analysis. Comparison of the results with data from two independent laboratories indicated large deviations for the arsenic and mercury concentrations.