Immunoenzyme assay of nonylphenol:study of selectivity and detection of alkylphenolic non-ionic surfactants in water samples

摘要

Immunoenzyme assay(ELIS A)is proposed and characterized for determination of alkylphenol ethoxylates,a primary class of manufactured non-ionic surfactants.The assay is based on the obtained polyclonal antibodies against nonylphenol(NP),the main stable intermediate of the decomposition of nonylphenol ethoxylates.A mixture of non-modified branched isomers of NP was applied as hapten coupled to protein carriers by Mannich reaction with the use of formaldehyde.The proposed ELISA format is based on immobilized NP-(soybean trypsin inhibitor)conjugate as a competitor of antigen molecules contained in the tested sample for binding with specific antibodies indirectly labeled via an anti-species immunoperoxidase conjugate.The developed ELISA allows to reveal NP with the limit of detection about 10 ng ml~(-1)and NP-related compounds such as octylphenol,alkylphenoletoxylates,alkylphenolcarboxylates and their halogenated derivatives.The ELISA was applied for assaying polluted water samples,namely influents and effluents from different wastewater treatment plants(WWTP)and tap water.ELISA and chromatographic data demonstrate good correlation(r=0.94),while ELISA gives higher values.Due to endocrine disrupting and other toxic activities of some metabolites of alkylphenolic non-ionic surfactants,the developed assay may be effectively,used in ecological monitoring and sanitary control.