Publication Date:
2022-05-25
Description:
Author Posting. © The Author(s), 2012. This is the author's version of the work. It is posted here by permission of John Wiley & Sons for personal use, not for redistribution. The definitive version was published in Rapid Communications in Mass Spectrometry 26 (2012): 2619–2626, doi:10.1002/rcm.6385.
Description:
Steroids are potent hormones that are found in many environments. Yet, contributions from
synthetic and endogenous sources are largely uncharacterized. The goal of this study was to
evaluate whether carbon isotopes could be used to distinguish between synthetic and endogenous
steroids in wastewater and other environmental matrices. Estrogens and progestogens were isolated from oral contraceptive pills using semi-preparative
liquid chromatography/diode array detection (LC/DAD). Compound purity was confirmed by
gas chromatography-flame ionization detection (GC-FID), gas chromatography/time-of-flight
mass spectrometry (GC/TOF-MS) and liquid chromatography/mass spectrometry using negative
electrospray ionization (LC/ESI-MS). 13C content was determined by gas
chromatography/isotope ratio mass spectrometry (GC/IRMS) and 14C was measured by
accelerator mass spectrometry (AMS). Synthetic estrogens and progestogens are 13C depleted (δ13Cestrogen = -30.0 ± 0.9 ‰; δ13Cprogestogen
= -30.3 ± 2.6 ‰) compared to endogenous hormones (δ13C ~ -16 ‰ to -26 ‰). The 14C content
of the majority of synthetic hormones is consistent with synthesis from C3 plant-based
precursors, amended with “fossil” carbon in the case of EE2 and norethindrone acetate.
Exceptions are progestogens that contain an ethyl group at carbon position 13 and have entirely
“fossil” 14C signatures. Carbon isotope measurements have the potential to distinguish between synthetic and
endogenous hormones in the environment. Our results suggest that 13C could be used to
discriminate endogenous from synthetic estrogens in animal waste, wastewater effluent, and
natural waters. In contrast, 13C and 14C together may prove useful for tracking synthetic
progestogens.
Description:
This work was supported by the Martin
Family Society of Fellows for Sustainability and by a U.S. Environmental Protection Agency
STAR graduate fellowship (FP-91713401).
Keywords:
Steroidal hormones
;
Ethynylestradiol (EE2)
;
Carbon isotopes (13C, 14C)
;
Oral contraceptive pill
;
Environmental forensics
Repository Name:
Woods Hole Open Access Server
Type:
Preprint
Format:
application/pdf
Permalink
