Determination of Organophosphorus Pesticides in Vegetables and Fruit by an Indirect Competitive Enzyme-Linked Immunosorbent Assay (ic-ELISA) and a Lateral-Flow Immunochromatographic (LFIC) Strip Assay

Abstract

Residues of pesticides in agricultural by-products may cause harm to human health. An indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) and a competitive form of lateral-flow immunochromatographic (LFIC) strip were developed for the determination of methyl parathion and triazophos in agricultural by-products. In the optimized system for ic-ELISA, the limits of detection (LODs) for methyl parathion and triazophos were 1.39 and 1.94 ng/mL. The linear ranges for methyl parathion and triazophos were from 7.90 to 200 ng/mL and 4.47 to 170.19 ng/mL. The recoveries from agricultural by-products ranged from 84.16 to 106.96% and the coefficients of variation were from 0.77 to 6.45%. In the optimized LFIC system, good linearity was obtained for methyl parathion and triazophos between 5 and 200 ng/mL. The LODs of the CG-LFIC strip for methyl parathion and triazophos were 2.17 and 4.21 ng/mL. The coefficients of variation of the test strip were from 0.73 to 8.34%. Pears, apples, cucumbers, and lettuces spiked with methyl parathion and triazophos were employed to characterize matrix effects using the LFIC strip. The ic-ELISA and LFIC strip were simple and practical for the rapid determination of organophosphorus pesticides in agricultural by-products. Furthermore, the LFIC strip was suitable for on-site testing and rapid screening.

Keywords:

• Agricultural by-products
• indirect competitive enzyme-linked immunosorbent assay (ic-ELISA)
• lateral-flow immunochromatographic (LFIC) strip
• methyl parathion
• triazophos

Acknowledgments

The authors acknowledge the support of the Beijing University of Chemical Technology-China-Japan Friendship Hospital Biomedical Transformation Engineering Research Center Joint Project (RZ2020-02) and the AECC Beijing Institution of Aeronautical Materials, and the National Key Research and Development Program of China (2016YFF0203703).

Disclosure statement

The authors declare that this work was conducted in the absence of commercial or financial relationships that may be construed as potential conflicts of interest.

Additional information

Funding

This work was supported by the Beijing University of Chemical Technology-China-Japan Friendship Hospital Biomedical Transformation Engineering Research Center Joint Project (RZ2020-02), and the AECC Beijing Institution of Aeronautical Materials and the National Key Research and Development Program of China (2016YFF0203703).