title: Ferrocene-based Diels-Alder derivatization for the determination of 1alpha-hydroxyvitamin D3 in rat plasma by high-performance liquid chromatography-electrospray tandem mass spectrometry.
abstract: A specific and sensitive liquid chromatography-electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) method has been developed for the determination of 1alpha-hydroxyvitamin D(3) (1alphaOHD(3)) in rat plasma. A new ferrocene-based Cookson-type reagent, 4-ferrocenylmethyl-1,2,4-triazoline-3,5-dione (FMTAD), designed and synthesized to be highly sensitive to vitamin D analogs in ESI, considerably improved the detection limit with 250 fg (359 amol)/injection. 1alphaOHD(3) in rat plasma was extracted with acetonitrile and then purified using Oasis HLB 96-well plates. After the precolumn derivatization with FMTAD, samples were subjected to LC/ESI-MS/MS employing a column-switching system. This method achieved a lower limit of quantitation of 5 pg from 0.1-mL plasma aliquots and 200-fold sensitivity of that without derivatization. The calibration curve (0.05-15 ng/mL) exhibited acceptable linearity (r>0.9966), intraassay precision ranged from 3.8 to 9.6%, interassay precision ranged from 3.0 to 17.0%, and accuracy was within 81.4-112.0%. This FMTAD derivatization method is considered very useful for determination of vitamin D analogs in ESI and applicable for biological samples.
authors.affiliation: Fuji Gotemba Research Labs, Chugai Pharmaceutical Co., Ltd., 1-135 Komakado, Gotemba, Shizuoka 412-8513, Japan. muraonoa@chugai-pharm.co.jp
authors.forename: Naoaki
authors.initials: N
authors.lastname: Murao
authors.forename: Masaki
authors.initials: M
authors.lastname: Ishigai
authors.forename: Nobuo
authors.initials: N
authors.lastname: Sekiguchi
authors.forename: Tadakatsu
authors.initials: T
authors.lastname: Takahashi
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Aso
mesh_terms: D000818:Animals; D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004355:Drug Stability; D006887:Hydroxycholecalciferols / Q000097:blood*; D051381:Rats; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: D006887:Hydroxycholecalciferols; C008088:alfacalcidol