CHROMATOGRAPHY

CHROMATOGRAPHY, Vol. 23 (2002), No. 2, pp. 65-71
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Original
Determination of Estrogens in Rat Brains Using Gas Chromatography/Mass Spectrometry/Mass Spectrometry
Kuniko Mitamura, Nanae Mikami, Yukiko Kambara, Emi Ohno and Kazutake Shimada*
Faculty of Pharmaceutical Sciences, Kanazawa University, 13°›1 Takara°›machi, Kanazawa 920°›0934, Japan

Abstract:
A standard addition determination method of estrone, estradiol and guaiacol estrones in rat brains using gas chromatography/mass spectrometry/ mass spectrometry (GC/MS/MS) was developed. Estrone and estradiol were extracted with liquid°›liquid extraction, purified successively with silica°›gel mini°›column chromatography, solid°›phase extraction and preparative HPLC. The obtained estrogens were derivatized to dimethylethylsilyl ethers followed by GC/MS/MS analysis. The concentrations of estrone and estradiol were 0°›44 and 0°›159 pg/g tissue (n= 4), respectively. On the other hand, an additional pretreatment procedure was necessary for determination of guaiacol estrones in rat brains. After the liquid°›liquid extraction, guaiacol estrones were acetylated with acetic anhydride°›pyridine and purified successively with silica°›gel mini°›column chromatography and solid°›phase extraction. The obtained guaiacol estrone acetates were hydrolyzed, derivatized to dimethylethylsilyl ethers and then applied to GC/MS/MS. Although the absolute recovery rates of guaiacol estrones spiked in brain homogenate were higher than 65%, these estrogens in rat brain were not determined.
Keywords: estrone, estradiol, guaiacol estrone, rat brain, standard addition method, gas chromatography/mass spectrometry/mass spectrometry


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