Detection of inorganic arsenic in rice using a field-deployable method with Cola extraction

Abstract

Rice is a staple food and known to accumulate inorganic arsenic (iAs), which is a class 1 carcinogen to humans. Arsenic field-deployable method kits, designed for water testing, are able to screen iAs in rice, to assure food safety and quick decision-making without the need for laboratory analysis. For the arsenic extraction within the field method, nitric acid is used. To make the field method on-site safer, cost-effective and easier to handle, the method was adapted using a Cola in the extraction process. The adapted field-deployable method was tested by screening a total of 30 rice and rice products from the Austrian market. To verify the results obtained by the Cola extraction field-deployable method, the obtained iAs concentration was compared to HPLC-ICP-MS results. The Cola extraction field method obtained an LOD of 39 µg iAs kg−1 rice, and with an average reproducibility of 14% RSD, the method was capable of recording no false-negative but 7% false-positive values at the 2023 updated European Commission (EC) limits for rice. All, but one, screened rice samples were within the EU limits for iAs in rice and rice products.

Atomic spectrometry update: review of advances in elemental speciation

“…However, the As extraction within the eld method utilises nitric acid. To make the eld method safer, cost-effective and easier to handle, the method has been further adapted by Wehmeier et al 54 using Cola in the extraction process, with the phosphoric acid in the drink presumably being the active extractant. The method was tested by screening a total of 30 rice and rice products (a variety of rice for infants, polished and parboiled rice as well as unpolished rice and rice crackers) obtained from the Austrian market.…”