Detection of triazolam and its hydroxy metabolites in rat hair by reversed-phase liquid chromatography with electrospray ionization mass spectrometry

Toshimasa Toyo'oka, Masayoshi Kanbori, Yusuke Kumaki, Tomoyuki Oe, Taketsune Miyahara, Yuji Nakahara

研究成果: Article査読

19 被引用数 (Scopus)

抄録

A sensitive method using reversed-phase liquid chromatography coupled with electrospray ionization mass spectrometry (LC-ESI-MS) for simultaneous determination of triazolam (TZ) and its hydroxy metabolites in hair has been developed. After the addition of deuterium-labeled 1-hydroxymethyltriazolam (1-HT-d4) as an internal standard, analytes in hair shaft and hair root samples were extracted with a basic medium, CH2Cl2/MeOH/28% NH4OH (20:80:2), at room temperature overnight. The chromatographic separation of the analytes was achieved using a 3-μm micro HPLC column (100 x 2.0-mm i.d.) with a gradient of acetonitrile in water containing 1% acetic acid as the mobile phase at a flow rate of 0.15 mL/min. The mass spectrometer was operated in selected-ion monitoring mode at quasi molecular ions [M+H]+ of TZ and its metabolites. Under the proposed conditions, the ranges of quantitation of TZ, 1-HT, and 4-HT were 0.1-10 ng/0.2 mL. The method has been applied to determine the hair shaft and hair root incorporation of TZ and its metabolites into Dark Agouti rats administered with 3 mg/kg or 6 mg/kg intraperitoneally twice a day for five days. Judging from the retention behavior by the chromatography and the mass spectra of the peaks detected, TZ, 1-HT, and 4-HT were incorporated in the hair shaft and the hair root. The concentration of 4-HT was the highest of all compounds detected. An unknown substance thought to be 1,4-diHT also appeared in both hair shaft and hair root samples. This substance was obtained from in vitro metabolic studies of TZ using rat liver microsome fraction and was accompanied by the other two metabolites, 1-HT and 4-HT. Structural elucidation was performed with online high-performance liquid chromatography-MS after acetylation of the substance with acetic anhydride and pyridine. This is the first report of the detection of the hydroxy metabolites of TZ in hair. The method has been found to be useful as a screening procedure of TZ intake in humans.

本文言語English
ページ(範囲)194-201
ページ数8
ジャーナルJournal of Analytical Toxicology
24
3
DOI
出版ステータスPublished - 2000 4
外部発表はい

ASJC Scopus subject areas

  • 分析化学
  • 環境化学
  • 毒物学
  • 健康、毒物学および変異誘発
  • 化学的な安全衛生

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