Quantification of steroid oestrogens in wastewater treatment by ELISA kits with an improved sample pretreatment protocol

摘要

Steroid oestrogens are endocrine disrupting chemicals(EDCs)active at part per trillion level in water,and oestrone(E1),17β-oestradiol(E2)and 17α-ethinyl oestradiol(EE2)are to be regulated for discharging from sewage treatment works(STWs)in the United Kingdom(UK)The trace concentrations and matrix complexity have made the quantification of steroid oestrogens a technique challenge.An improved sample pretreatment protocol with graphitized carbon black(GCB)solid phase extraction(SPE) cartridges were used for crude sewage,primary effluent,secondary effluent and final effluent at a sewage treatment works as well as a water sample from the downstream receiving river.E1.E2 and EE2 were quantified by both enzyme-linked immunosorbent assay(ELlSA)kits and HPLC-MS(TOF)for comparison.The performance of GCB SPE were also evaluated by comparing the measured oestrogen concentrations for the same sample pretreated bv C18 SPE cartridges.Without followed chromatographic clean-up,ELlSA analysis after C18 SPE gave a high overestimate for crude sewage and primary effluent.The GCB SPE with selective elution effectively minimized the overestimate.with the results obtained by ELISA kitS and HPLC-MS(TOF) in very good agreement.The limit of detection for ELISA kits was 0.5ng/L.