Identification and quantitation of 16α-hydroxy c21 steroid sulphates in plasma from pregnant women

Plasma steroids from 11 women in the last trimester of pregnancy were separated into conjugate class by chromatography on Sephadex LH-20. Fractions corresponding to mono- and disulphate conjugates were solvolyzed and the free steroids were separated by lipophilic gel chromatography into groups containing mono-, di- and trihydroxy steroids, respectively. Trimethylsilyl ether derivatives were prepared and repetitive-scanning gas chromatography-mass spectrometry (GC-MS) was used to characterize and quantitate the following 16α-hydroxy steroids in the monosulphate fraction: 3α,16α:-dihydroxy-5α-pregnan-20-one (range 8–80 ng/ml), 3β,16α-dihydroxy-5α-pregnan-20-one (6–55 ng/ml), 5α-pregnane-3α,16α,20α-triol (9–31 ng/ml) and 5α-pregnane-3β,16α,20α-triol (11–77 ng/ml). These compounds were also present as disulphates although at 5–50 times lower concentrations.