Validation of a Monoclonal Enzyme Immunoassay for the Determination of Carbofuran in Fruits and Vegetables

Abstract

The N-methylcarbamate pesticide carbofuran is a very important insecticide used worldwide. In the present work, the validation of a monoclonal antibody-based enzyme immunoassay (ELISA) to determine this compound in fruits and vegetables is described. The immunoassay is a competitive heterologous ELISA in the antibody-coated format, with an I(50) value for standards in buffer of 740 ng/L and with a dynamic range between 200 and 3100 ng/L. For recovery studies, peppers, cucumbers, strawberries, tomatoes, potatoes, oranges, and apples were spiked with carbofuran at 10, 50, and 200 ppb. After liquid extraction, analyses were performed by ELISA on extracts purified on solid-phase extraction (SPE) columns and crude, nonpurified extracts. Depending on the crop, mean recoveries in the 43.9--90.7% range were obtained for purified samples and in the 90.1--121.6% range for crude extracts. The carbofuran immunoassay performance was further validated with respect to high-performance liquid chromatography (HPLC) with postcolumn derivatization and fluorescence detection (EPA Method 531.1). Samples were spiked with carbofuran at several concentrations and analyzed as blind samples by ELISA and HPLC after SPE cleanup. The correlation between methods was very good (y = 0.90x + 2.66, r(2)() = 0.958, n = 25), with HPLC being more precise than ELISA (mean coefficients of variation of 4.1 and 11.5%, respectively). The immunoassay was then applied to the analysis of nonpurified extracts of the same samples. Results also compared very well with those obtained by HPLC on purified samples (y = 1.02x + 10.44, r(2)() = 0.933, n = 29). Therefore, the developed immunoassay is a suitable method for the quantitative and reliable determination of carbofuran in fruits and vegetables even without sample cleanup, which saves time and money and considerably increases the sample throughput.

The Present State and Perspective on Simple and Rapid Immunochemical Detection for Pesticide Residues in Crops

“…Although fundamentally, the ELISA results were nearly equal to the chromatographic results, or tended to somewhat overestimate theoretical values except for some imidacloprid results, when considering average recovery rates as a whole (Fig. 9), the evaluated ELISAs showed tolerable agreement with the chromatographic methods for the three pesticides, and it can be concluded that all evaluated ELISAs are practical analytical techniques that can be used as quantitative screening methods to detect pesticides in crop samples, as described in several related reports 1,8,19,28 .…”

Development of a Bispecific Monoclonal Antibody to Pesticide Carbofuran and Triazophos Using Hybrid Hybridomas

“…Traditionally, the analytical method for carbofuran is gas chromatography (Liska and Slobodnik 1996) and liquid chromatography with postcolumn derivatization and fluorescene detection (Barcelo 1993). Immunoassay for carbofuran based on monoclonal antibody had also been described (Abad and others 1997; Moreno and others 2001; Jin and others 2006).…”

Construction of an impedimetric immunosensor for label-free detecting carbofuran residual in agricultural and environmental samples

“…Many techniques for the determination of carbofuran have been developed including gas chromatography (GC) (Leppert, Markle, & Helt, 1983), high performance liquid chromatography (HPLC) (Nogueira, Sandra, & Sandra, 2004), liquid chromatography-mass spectrometry (LC-MS) (Honing, Barcel o, van Baar, & Brinkman, 1995;Soler et al, 2007), gas chromatography-mass spectrometer (GCeMS) (Petropoulou, Gikas, Tsarbopoulos, & Siskos, 2006), chemiluminescence (P erez-Ruiz, Martínez-Lozano, Tom as, & Martín, 2002), enzyme-linked immunosorbent assay (ELISA) (Yang et al, 2008;Moreno et al, 2001;Abad, Moreno, & Montoya, 1997;Jourdan, Ardid, Chapuy, Eschalier, & Bars, 1995), fluorimetry (Li, Zhang, Zhao, & Hu, 2010), amperometric immunosensor (Sun, Zhu, & Wang, 2011), and microcantilever sensor (Wang, Wang, Liu, & Hu, 2011). Carbofuran is thermally unstable and decomposes to the phenol under the usual gas chromatography conditions (Li ska & Slobodík, 1996).…”