New paper on Detection of Thioarsenates in Rice
2021-02-10
Andrea has published the first paper of her Ph.D., "Detection of Thioarsenates in Rice Grains and Rice Products" in which she improves a method for acid As extraction from rice products in order to detect ThioArsenates, using now an enzymatic extraction.
Abstract
Inorganic and methylated thioarsenates have recently been reported to contribute substantially to arsenic (As) speciation in paddy-soil pore waters. Here, we show that thioarsenates can also accumulate in rice grains and rice products. For their detection, a method was developed using a pepsin–pancreatin enzymatic extraction followed by chromatographic separation at pH 13. From 54 analyzed commercial samples, including white, parboiled and husked rice, puffed rice cakes, and rice flakes, 50 contained dimethylmonothioarsenate (DMMTA) (maximum 25.6 μg kg–1), 18 monothioarsenate (MTA) (maximum 5.6 μg kg–1), 14 dimethyldithioarsenate (DMDTA) (maximum 2.8 μg kg–1), and 5 dithioarsenate (DTA) (maximum 2.3 μg kg–1). Additionally, we show that the commonly used nitric acid extraction transforms MTA to arsenite and DMMTA and DMDTA to dimethylarsenate (DMA). Current food guidelines do not require an analysis of thioarsenates in rice and only limit the contents of inorganic oxyarsenic species (including acid-extraction-transformed MTA), but not DMA (including acid-extraction-transformed DMMTA and DMDTA).
Link: https://eref.uni-bayreuth.de/63009/
Congratulations to Andrea, Carolin, and Britta! And happy International Day of Women and Girls in Science! (21/02/2021)