研究了聚联苯乙烯(SDB)和石墨化碳黑(GCB)固相萃取用于样品前处理对污水样中雌二醇(E2)和乙炔基雌二醇(EE2)的酶联免疫吸附检测(ELISA)定量分析可靠性的影响。采用GCB固相萃取可对E2和EE2进行分步洗提,相比SDB固相萃取在污水厂原水样中E2和EE2的加标回收率分别从181.4%和122.6%降至113.3%和109.4%,相对标准偏差均降至10.0%以下;在污水厂尾水样中E2的加标回收率则分别从144.2%降至93.5%,而EE2无明显变化,相对标准偏差均从接近10.0%降至8.0%以下。利用液相色谱-飞行时间质谱联用对污水厂原水样的平行分析的结果表明采用GCB固相萃取可比采用SDB固相萃取降低38%的E2检测假阳性和15%的EE2检测假阳性。
This paper studies the effect of styrene divinyl benzene (SDB) solid phase extraction (SPE) and graphitized carbon black (GCB) SPE on the quantification of estradiol (E2) and ethinyl estradiol (EE2) by enzyme-linked immunosorbent assay (ELISA) kit. The recovery rates of E2 and EE2 in spiked raw sewage samples drop from 181.4% and 122.6% to 113.3% and 109.4% respectively with the relative standard deviations dropped to below 10.0%. The reovery rate of E2 in final effluent decreases from 144.2% to 93.5% whilst the rate of EE2 has marginal variation,and the relative standard deviation drops from approximately 10.0% to lower than 8.0%. The estrogen levels measured by ELISA are collated with those measured by parellel liquid chromatrography coupled with time of flight mass spectrometry (HPLC-MS(TOF)). GCB SPE with step elution is able to separate E2 and EE2 from the matrices thus reduces the cross reaction rate. GCB SPE decreases 38% and 15% false positives for E2 and EE2 ELISA analysis compared with SDB SPE. ELISA quantification with this improved GCB SPE pretreatment has the advantages of low cost and time-saving over the chemical analysis.