Identification of oestrogen metabolites in human urine by capillary gas chromatography and mass spectrometry

Abstract

Oestrogen metabolites from the urine of males and pregnant and non-pregnant females were enriched by a procedure involving column chromatography on adsorber resins, gels and ion exchangers, enzymatic solvolysis and extraction, thereby separating the oestrogens from most of the interfering material. After derivatization of the oestrogens as their trimethylsilyl ethers profiles were measured with a fused silica column and a flame ionization detector by gas chromatography. Using a combination of capillary gas chromatography and mass spectrometry approximately 50 oestrogen metabolites were detected in the human urine of males and females, of which 19 were unknown urine compounds. Not all could be identified definitely owing to the lack of reference material. Mass spectra of trimethylsilylated oestrogens with functional groups at position 11 (11-dehydroestradiol, 11-dehydroestrone and 11 beta-hydroxyestrone) were discussed in their common and discernible fragmentations.

Review of the effects of 17α‐estradiol in humans: a less feminizing estrogen with neuroprotective potential

“…In another study, Luukkainen and Adlercreutz [1965] were unable to detect 17a-estradiol in the urine of pregnant women, though they did find 11-dehydro-17a-estradiol (of unknown origin; that is, it may not have arisen via 17a-estradiol). More advanced analytical techniques showed 17a-estradiol to be present as a minor component of 50 or more steroids identified by capillary GC/MS in urine from men and from both pregnant and nonpregnant women [Gerhardt et al, 1989]. Luukkainen [1969, 1970] also identified a number of estrogens in various biological materials from pregnant women.…”

“…Hobe et al [2002] further suggested that this paucity of 17a-estradiol is due to the low activity of the enzyme steroid 17a-hydroxy oxidoreductase in humans, and they also noted that other investigators have suggested the possibility of 17a-estradiol arising from aromatization of epi-testosterone. Estrogens have been studied analytically in samples from adult humans using a variety of techniques, including gas chromatography and mass spectrometry (GC/MS) [Gerhardt et al, 1989]. In an early study, 17a-estradiol was not detected in pooled samples of human pregnancy urine, although there was some evidence of its presence in one individual [Schott and Katzman, 1964].…”

“…Proof that 17a-estradiol and its conjugates were endogenous substances in humans was difficult for researchers to establish in early studies, but more advanced analytical techniques have allowed detection of 17a-estradiol and its conjugates by multiple laboratories at low levels in both women and men [see, e.g., Gerhardt et al, 1989]. Hobe et al [2002] concluded from the available studies that 17a-estradiol had been found naturally in the blood and urine of many animal species, but in human urine only in limited cases or at low concentrations.…”