Simultaneous Analysis of Natural Free Estrogens and Their Sulfate Conjugates in Wastewater

Abstract

Natural estrogens from humans increasingly attract attention because of their strong endocrine disrupting potency. The discharge of sewage water is considered as the most important source of these endocrine disrupting chemicals (EDCs) in the environment. Therefore, a GC-MS method was developed for the simultaneous analysis of six natural free estrogens and their sulfate conjugates in municipal wastewater, in which natural free estrogens and sulfate conjugates were successfully separated from an Oasis HLB solid phase extraction (SPE) cartridge with two different eluents, and the sulfate conjugates were then transformed to their corresponding free estrogens by acid solvolysis. Before the analysis with GC-MS, samples were derivatized by N,O-bis (trimethylsilyl) trifluoroacetamide (BSTFA) plus 1% trimethylchlorosilane (TMCS) at 808C for 40 min. Satisfactory recoveries ranging from 64 to 112.3% were obtained by spiking ultra-purified water, raw, and treated municipal wastewater with the six estrogens at 50, 100, and 50 ng/L, respectively. The method was successfully applied to wastewater samples from one WWTP, which suggested that E1 was the dominant natural estrogens in effluent and E3-3S was one of the conjugates possibly occurring in the effluent.

De-conjugation behavior of conjugated estrogens in the raw sewage, activated sludge and river water

“…There is some evidence that the glucuronide forms are very susceptible to de-conjugation but much less certainty on the fate of the sulfate forms [4][5][6]. Unlike the glucuronides, residues of sulfate conjugates have been detected in the aquatic environment [6][7][8], indicating incomplete degradation at least of estrone-3-sulfate (E1-3S) in the sewage treatment plant (STP). In trying to assess risk, some have argued that both conjugate families are potentially available to conversion back to their parent forms [9], whilst others insist only the glucuronide form is relevant and the sulfate forms can be ignored [1].…”

Removal of Natural Estrogens and Their Conjugates in Municipal Wastewater Treatment Plants: A Critical Review

“…76 With the two different functional groups, these conjugates possess two different properties over their natural estrogens: (1) the polarities of natural estrogen conjugates are stronger than those of natural estrogens, which makes them more favorable for eliminating from human and animal bodies; 81,89 (2) the estrogenic activities of estrogen conjugates are much weaker when they are compared to natural estrogens. 90 The conjugation of natural estrogens in human and animal acts as potential "detoxification" reactions that may protect the cell from estrogen-mediated mitogenicity and mutagenesis.…”

“…Natural estrogen conjugates differentiate them from their corresponding natural estrogens are that they have sulfate, and/or glucuronide functional groups (Figure ), and these conjugates can be deconjugated to their corresponding natural estrogens with arylsulfatase or β-glucuronidase derived from microorganisms or organs of higher organisms . With the two different functional groups, these conjugates possess two different properties over their natural estrogens: (1) the polarities of natural estrogen conjugates are stronger than those of natural estrogens, which makes them more favorable for eliminating from human and animal bodies; , (2) the estrogenic activities of estrogen conjugates are much weaker when they are compared to natural estrogens . The conjugation of natural estrogens in human and animal acts as potential “detoxification” reactions that may protect the cell from estrogen-mediated mitogenicity and mutagenesis .…”

MCX based solid phase extraction combined with liquid chromatography tandem mass spectrometry for the simultaneous determination of 31 endocrine-disrupting compounds in surface water of Shanghai

“…However, the excessive steps are tedious and may cause loss of compounds and reduce the recoveries. SPE with HLB cartridge has been employed in the detection of natural and synthetic estrogens and industrial compounds [3,14,16]. Therefore, SEP with MCX cartridge was employed in this study.…”

“…Gas chromatography tandem mass spectrometry (GC-MS) and liquid chromatography tandem mass spectrometry (LC-MS/MS) have been employed for the analysis of these compounds [11][12][13]. Many analytical methods employing GC-MS have been developed for several kinds of EDCs in various samples [14][15][16][17]. Generally, derivatization of the compounds is a necessary step prior to GC-MS in order to improve selectivity and sensitivity in these methods.…”