title: Highly sensitive determination of estrone and estradiol in human serum by liquid chromatography-electrospray ionization tandem mass spectrometry.
abstract: A highly sensitive and specific quantification method of estrone and estradiol in human serum was described based upon the use of picolinoyl derivatization and liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS) in a positive mode. Estrogens were treated with picolinoyl chloride hydrochloride or picolinic acid and 2-methyl-6-nitrobenzoic anhydride followed by a solid-phase extraction with ODS cartridge. Picolinoyl derivatization proceeded quantitatively even in a microscale, and the picolinoyl esters provided simple positive ESI-mass spectra showing [M+H](+) as base peaks for these estrogens. The picolinoyl derivatives of these estrogens showed 100-fold higher detection response compared to underivatized intact molecules by LC-ESI-MS (selected reaction monitoring). Using this derivatization, estrogens spiked in the charcoal treated human serum samples were analyzed with limit of quantification (LOQ), intra-day accuracy and precision of 1.0pg/ml, 96.0% and 9.9% for estrone, and 0.5pg/ml, 84.4% and 12.8% for estradiol, respectively. Estrone and estradiol added to the crude serum samples were recovered with comparable LOQ and accuracy obtained for the charcoal treated serum samples as well.
authors: Faculty of Pharmaceutical Science, Tohoku Pharmaceutical University, 4-1 Komatsushima 4-Chome, Sendai, Japan. kyama@tohoku-pharm.ac.jp
authors: Kouwa
authors: K
authors: Yamashita
authors: Mitsunobu
authors: M
authors: Okuyama
authors: Yoko
authors: Y
authors: Watanabe
authors: Seijiro
authors: S
authors: Honma
authors: Sayuri
authors: S
authors: Kobayashi
authors: Mitsuteru
authors: M
authors: Numazawa
mesh_terms: D002853:Chromatography, Liquid; D004958:Estradiol / Q000097:blood* / Q000737:chemistry / Q000302:isolation & purification; D004970:Estrone / Q000097:blood* / Q000737:chemistry / Q000302:isolation & purification; D005260:Female; D006801:Humans; D010848:Picolinic Acids / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D010848:Picolinic Acids; D012997:Solvents; D004970:Estrone; D004958:Estradiol; C030614:picolinic acid