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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.
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| Keywords: | estrone, estradiol, guaiacol estrone, rat brain, standard addition method, gas chromatography/mass spectrometry/mass spectrometry |
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