Determination of irradiation histories of raw beef livers using liquid chromatography–tandem mass spectrometry of 5, 6-dihydrothymidine. (1st February 2017)

• Record Type: Journal Article
• Authors: Fukui, Naoki; Takatori, Satoshi; Kitagawa, Yoko; Okihashi, Masahiro; Ishikawa, Etsuko; Fujiyama, Takatomo; Kajimura, Keiji; Furuta, Masakazu; Obana, Hirotaka
• Is Part Of: Food chemistry. Volume 216(2017)
• Page Start: 186
• Page End: 193
• Publication Date: 2017-02-01
• Subjects: Irradiated food -- DNA -- 5, 6-Dihydrothymidine -- Beef livers -- LC–MS/MS; Food -- Analysis -- Periodicals; Food -- Composition -- Periodicals; 664
• DOI: 10.1016/j.foodchem.2016.08.036
• Languages: English
• ISSNs: 0308-8146

Abstract

Highlights: Irradiation history of raw beef liver was determined by LC–MS/MS analysis of DHdThd. DHdThd was specifically formed from thymidine moiety by irradiation. DHdThd would be a suitable marker of the irradiation history of raw beef livers. The method's wide applicability and robustness. DHdThd, 5, 6-dihydrothymindine. Abstract: A method for detecting irradiation histories of raw beef livers was developed by measuring 5, 6-dihydrothymidine (DHdThd) using liquid chromatography–tandem mass spectrometry (LC–MS/MS). Liver DNA was extracted using phenol–chloroform extraction followed by precipitation in 50% ethanol. DNA was then enzymatically digested and nucleosides were purified using an OASIS MCX column. DHdThd and thymidine (dThd) contents of resulting test solutions were analyzed using LC–MS/MS. DHdThd was detected specifically after γ-irradiation. Concentration ratios of DHdThd to dThd in the test solutions increased dose-dependently after irradiation at 1.0–11.3 kGy, which included the practical dose for sterilization of 2–7 kGy. Dose–response curves from beef livers of individual animals almost overlapped. Thus, this method is a candidate for the detection of irradiation histories of foods from which DNA can be extracted.