Determination of irradiation histories of raw beef livers using liquid chromatography-tandem mass spectrometry of 5,6-dihydrothymidine.
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 1.0-11.3kGy, which included the practical dose for sterilization of 2-7kGy. 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.
Division of Food Chemistry, Osaka Prefectural Institute of Public Health, Nakamichi 1-3-69, Higashinari-ku, Osaka, Japan; Laboratory of Quantum-Beam Chemistry and Biology, Radiation Research Center, Osaka Prefecture University, 1-2 Gakuen-cho, Sakai, Osaka, Japan.
Naoki
N
Fukui
Division of Food Chemistry, Osaka Prefectural Institute of Public Health, Nakamichi 1-3-69, Higashinari-ku, Osaka, Japan. Electronic address: sts-tkt@iph.pref.osaka.jp.
Satoshi
S
Takatori
Division of Food Chemistry, Osaka Prefectural Institute of Public Health, Nakamichi 1-3-69, Higashinari-ku, Osaka, Japan.
Yoko
Y
Kitagawa
Division of Food Chemistry, Osaka Prefectural Institute of Public Health, Nakamichi 1-3-69, Higashinari-ku, Osaka, Japan.
Masahiro
M
Okihashi
Laboratory of Quantum-Beam Chemistry and Biology, Radiation Research Center, Osaka Prefecture University, 1-2 Gakuen-cho, Sakai, Osaka, Japan.
Etsuko
E
Ishikawa
Laboratory of Quantum-Beam Chemistry and Biology, Radiation Research Center, Osaka Prefecture University, 1-2 Gakuen-cho, Sakai, Osaka, Japan.
Takatomo
T
Fujiyama
Division of Food Chemistry, Osaka Prefectural Institute of Public Health, Nakamichi 1-3-69, Higashinari-ku, Osaka, Japan.
Keiji
K
Kajimura
Laboratory of Quantum-Beam Chemistry and Biology, Radiation Research Center, Osaka Prefecture University, 1-2 Gakuen-cho, Sakai, Osaka, Japan.
Masakazu
M
Furuta
Division of Food Chemistry, Osaka Prefectural Institute of Public Health, Nakamichi 1-3-69, Higashinari-ku, Osaka, Japan.
Hirotaka
H
Obana
D000818:Animals; D002417:Cattle; D002853:Chromatography, Liquid / Q000379:methods*; D004247:DNA / Q000032:analysis; D008099:Liver / Q000737:chemistry / Q000528:radiation effects*; D053719:Tandem Mass Spectrometry / Q000379:methods*; D013936:Thymidine / Q000031:analogs & derivatives* / Q000032:analysis
C029949:5,6-dihydrothymidine; D004247:DNA; D013936:Thymidine
5,6-Dihydrothymidine; Beef livers; DNA; Irradiated food; LC–MS/MS