Paulson J, Lindberg C
Bioanalytical Chemistry, AB Draco, Lund, Sweden.
J Chromatogr. 1991 Aug 21;554(1-2):149-54. doi: 10.1016/s0021-9673(01)88445-4.
The 21-hydroxyl group of cortisol was selectively acetylated under mild conditions without affecting the more sterically hindered 11 beta- and 17 alpha-hydroxyl groups. The reaction was performed with a mixture of acetic anhydride and triethylamine in acetonitrile and was complete in less than 15 min at room temperature. The thermospray mass spectrum of cortisol 21-acetate showed minimal fragmentation with the [M + H]+ ion as the base peak. High sensitivity was achieved for acetylated cortisol during selected ion monitoring, the signal-to-noise ratio being increased by a factor of about 4, compared to underivatized cortisol. The limit of detection of cortisol 21-acetate was estimated at 0.24 pmol injected, making thermospray liquid chromatography-mass spectrometry competitive with gas chromatography-mass spectrometry for the determination of cortisol in biological fluids.
在温和条件下，皮质醇的21 - 羟基被选择性乙酰化，而不会影响空间位阻更大的11β - 和17α - 羟基。该反应在乙腈中用乙酸酐和三乙胺的混合物进行，在室温下不到15分钟即可完成。皮质醇21 - 乙酸酯的热喷雾质谱显示，以[M + H]+离子作为基峰时，碎片最少。在选择离子监测期间，乙酰化皮质醇实现了高灵敏度，与未衍生化的皮质醇相比，信噪比提高了约4倍。皮质醇21 - 乙酸酯的检测限估计为注入0.24皮摩尔，这使得热喷雾液相色谱 - 质谱法在生物流体中皮质醇的测定方面与气相色谱 - 质谱法具有竞争力。
