Homogeneous fluoroimmunoassay of a pyrethroid metabolite in urine

Evgenia G. Matveeva, Guomin Shan, Ian M. Kennedy, Shirley J. Gee, Donald W. Stoutamire, Bruce D. Hammock

Research output: Contribution to journalArticle

14 Scopus citations

Abstract

Pyrethroids are widely used in agriculture as insecticides. In this study, we describe a simple one-step homogeneous fluoroimmunoassay for the glycine conjugate of phenoxybenzoic acid (PBAG), a putative pyrethroid metabolite that may be used as a biomarker of exposure to pyrethroids. Quenching fluoroimmunoassay (QFIA) is based on the competition of labeled and non-labeled pesticide for binding with antibodies and the resulting calibration curve is based on the relationship between analyte concentration and fluorescence quenching of labeled pesticide by specific antibodies. We developed a QFIA for PBAG in aqueous solution using fluorescein-labeled PBAG and polyclonal antibodies. The estimated IC50 (analyte concentration giving 50% inhibition of quenching) for PBAG was 4.5 nM. The detection limit (DL) was 0.9 nM. The dynamic range of the calibration curve was 2-50 nM. The average analytical recovery obtained by applying the method to urine samples (400- or 1000-fold urine dilution) was 85-111%. This demonstrates the QFIA to be a very simple and rapid detection method for PBAG; no washing steps and no enzyme conjugates were required.

Original languageEnglish (US)
Pages (from-to)103-117
Number of pages15
JournalAnalytica Chimica Acta
Volume444
Issue number1
DOIs
StatePublished - Oct 12 2001

Keywords

  • Fluorescence quenching
  • Homogeneous fluoroimmunoassay
  • Polyclonal antibodies
  • Pyrethroid metabolite
  • Urine

ASJC Scopus subject areas

  • Biochemistry
  • Analytical Chemistry
  • Spectroscopy
  • Environmental Chemistry

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  • Cite this

    Matveeva, E. G., Shan, G., Kennedy, I. M., Gee, S. J., Stoutamire, D. W., & Hammock, B. D. (2001). Homogeneous fluoroimmunoassay of a pyrethroid metabolite in urine. Analytica Chimica Acta, 444(1), 103-117. https://doi.org/10.1016/S0003-2670(01)01161-8