Simultaneous determination of 6β- and 6α-hydroxycortisols and 6β-hydroxycortisone in human urine by stable isotope dilution mass spectrometry

A capillary gas chromatographic-mass spectrometric method for the simultaneous determination of 6 beta-hydroxycortisol (6 beta-OHF, 6 beta,11 beta,17 alpha,21-tetrahydroxypregn-4-ene-3,20-dione), 6 alpha-hydroxycortisol (6 alpha-OHF, 6 alpha,11 beta,17 alpha,21-tetrahydroxypregn-4-ene-3,20-dione) and 6 beta-hydroxycortisone (6 beta-OHE, 6 beta,17 alpha,21-trihydroxypregn-4-ene-3,11,20-trione) in human urine is described. Deuterium-labelled compounds, 6 beta-[1,1,19,19,19-H-2(5)]OHF (6 beta-OHF-d(5)), 6 alpha-[1,1,19,19,19-H-2(5)]OHF (6 alpha-OHF-d(5)) and 6 beta-[1,1,19,19,19-H-2(5)]OHE (6 beta P-OHE-d(5)) were used as internal standards. Quantitation was carried out by selected-ion monitoring of the characteristic fragment ions ([M-31](+)) of the methoxime-trimethylsilyl (MO-TMS) derivatives of 6 beta-OHF, 6 alpha-OHF and 6 beta-OHE. The sensitivity, specificity, precision and accuracy of the method were demonstrated to be satisfactory for measuring 6 beta-OHF, 6 alpha-OHF and 6 beta-OHE in human urine. (C) 2000 Elsevier Science B.V. All rights reserved.