Simultaneous determination of estriol, -estradiol, 17ethinyl estradiol and estrone employing solid phase extraction (SPE) and high performance liquid chromatography (HPLC)

Abstract

The hormones β-estradiol, estrone, estriol and 17α-ethinyl estradiol have been detected in effluents because the current processes of sewage treatment are unable to remove them; the residue is being discarded into receiving bodies. These substances cause harm to human and environmental health (aquatic and terrestrial organisms), which is why there is a need for monitoring them. In the present work, we used SPE methodology using C18 cartridges and a HPLC method for simultaneous determination of these hormones in effluent samples. HPLC analysis was performed in isocratic mode, mobile phase 50% ACN: H2O pH 3.0, C18 column, flow 1 mLmin-1 Injection 10  L,  = 281nm,  = 40 ° C. The measurements ranged from 3.75 gL-1 for 17-ethinylestradiol to 7.75 gL-1 for estriol. Detection limits varied from 1.12 gL-1 for 17-ethinylestradiol to 2.32 gL-1 for estriol. In the range of 0-60 gL-1 the hormones analyzed showed high correlation coefficient (R2  0.99). The precision (inter- and intra-assay) assessed at 4 different concentration levels presented coefficient of variance (%CV) and accuracy lower than 3%. Different tests have been performed showing that the SPE extraction using acetonitrile elution with methanol showed recovery values higher than 75%. The validated methodology was applied in the analysis of a sample of water from Tubarão Stream (Santo André, SP) highlighting the presence of the hormones estriol 0.4 gL 1 and estrone 0.32 gL-1. The proposed methodology was found to be adequate for the determination of estrogen hormones in natural water.