Highly Sensitive Enzyme-Linked Immunosorbent Assay for Chlorpyrifos. Application to Olive Oil Analysis

Abstract

Highly sensitive enzyme-linked immunoassays for chlorpyrifos, one of the most applied insecticides, are presented. Several haptens were synthesized for immunoreagent production and ELISA development. The best immunoassays obtained are based on an indirect coated-plate immunoassay format. Two assays were optimized; one shows a limit of detection of 0.3 ng L(-1), an I50 of 271 ng L(-1), and a dynamic range between 4 and 16 474 ng L(-1). The other one has a limit of detection of 0.07 ng L(-1), an I50 of 7 ng L(-1), and a dynamic range between 0.4 and 302 ng L(-1). The assays were used to quantify chlorpyrifos in olive oil using a simple and rapid sample extraction procedure. The good recoveries achieved in both assays (109% mean value) and the agreement with values given by the GC reference method (110% mean value) indicate their potential for either screening or laboratory quantification.

A sensitive monoclonal antibody-based enzyme-linked immunosorbent assay for chlorpyrifos residue determination in Chinese agricultural samples

“…In previous studies on chlorpyrifos ELISA, a slight acidic pH (6.0 or 6.5) was selected as the optimal value. [9,21] It was found that further increasing pH decreased or had no effect on sensitivity. The difference may be due to the various tolerance of different antibodies to acidic or basic condition.…”

“…[22] Brun [9] selected 0.5 % Tween as the optimal detergent for chlorpyrifos ELISA determination. However, the opposite effect of Tween 20 has also been reported.…”

“…Although the non-optimized and optimized assay had a negligible CR with many tested compounds, the latter was less interfered by chlorpyrifosmethyl and chlorpyrifos-oxon. Brun et al [9] developed two optimized ELISAs for chlorpyrifos with IC 50 271 ng/mL and 7 ng/mL, but both showed a higher interference from chlorpyrifos-methyl (140 % and 50 %). Such interference had been reported by many other researchers.…”

“…Manclus [7,10] used a monoclonal antibody (Mab) coated to microtiter plates to analyze chorpyrifos in water and achieved a limit of detection (LOD) of 6.0 ng/mL. Using polyclonal antibody, Brun [9] established an indirect competitive immunoassay, with a LOD of 10 ng/g in olive oil.…”

Development of an adsorptive catalytic stripping voltammetric method for the determination of an endocrine disruptor pesticide chlorpyrifos and its application to the wine samples

“…Analysis of Chlorpyrifos in different food matrixes is conventionally carried out by gas chromatography (GC) by using NPD [10], ECD [3], and MS detectors [11][12][13]. Liquid chromatography (HPLC) [14], immunoassay-based techniques, such as enzyme linked immunosorbent assay (ELISA) [15], and liquid chromatography determinations combined with ELISA have also been reported [16,17]. Major techniques for extraction and concentration of pesticides prior to the chromatographic separation in wine are liquid-liquid extraction (LLE) and solid-phase extraction (SPE), solid-phase micro extraction (SPME).…”