Determination of the herbicide acetochlor by fluorescence polarization immunoassay

Abstract

Acetochlor[2-chloro-N -(ethoxymethyl)-N -(2-ethyl-6-methylphenyl)acetamide] belongs to chloroacetanilide herbicides, which have been widely introduced into the world agricultural practice [1][2][3]. Chloroacetanilide herbicides are relatively unstable in the environment and undergo degradation within six months; this is a valuable property of these herbicides. However, they can be detected in reservoirs, fish, and products of plant origin in amounts higher than maximum permissible levels as a result of their agricultural use. Acetochlor is a comparatively new pesticide; it was first registered in the United States in 1994. It has now replaced related compounds because of its better biodegradability and a relatively small carcinogenic effect. However, as well as the majority of pesticides, acetochlor is genotoxic, as was exemplified in plants, rats, and human lymphocytes [1]. Therefore, acetochlor residues should be monitored in natural samples such as water and soil.Chromatographic techniques, such as gas chromatography with atomic emission [4] or mass-spectrometric detection [5, 6], high-performance liquid chromatography with various detection techniques [7,8], and capillary electrophoresis [9] are commonly used for determining herbicides, in particular, acetochlor. These techniques are highly sensitive and accurate; however, they are also expensive and time-consuming. At the same time, it is necessary to perform simple and rapid screening in a great number of samples in order to detect herbicide-contaminated areas.Immunochemical techniques based on the specific binding of an analyte to corresponding specific antibodies are well suitable for this purpose. Enzyme immunoassay (EIA) has received the widest acceptance; the theory and practice of EIA was described in detail [10]. The use of EIA for the determination of pesticides has been reported in many reviews [11][12][13][14][15][16].EIA techniques are highly sensitive and simple; they can be performed under field conditions at the sampling site [17]. Since the 1990s, EIA has been used with increasing frequency for the screening of pesticides in natural and food samples. The current status, applicability, and prospects for the widespread use of immunochemical techniques for the determination of pesticides in the environment were considered in a review [18]. Recent data on the development and use of EIA for pesticides in Russia were published in [19][20][21].Earlier, we developed immunochemical methods for the determination of acetochlor by ELISA [22] and with the use of an immunosensor [23] or a piezosensor [24]. However, these are multistep procedures, and the time of analysis is 2 to 3 h. Moreover, ELISA includes a number of steps of pipetting and washing with the use of several specific reagents; it requires qualified personnel. Therefore, the recent trend has been toward the development of nonseparation (homogeneous) immunoassay techniques, which significantly improve socalled high-throughput screening (HTS) [25]. Although an optimum immunoassay procedure for...

Comparative Study of Herbicides for Pre-Emergence Weed Control in Maize (Zea mays L.) in Derived Savanna of Nigeria

“…This is similar in effect with other herbicides evaluated in the study. Notwithstanding, it comparative advantage of this herbicide as one of the most widely used herbicides in maize in the USA due to its better biodegradability and relatively small cancer-causing effect [18,19], need to be ascertained in other herbicides aside the economic return in maize production when applied.…”

Development of Fluorescence Polarization Immunoassay With scFv to Detect Fumonisin Bs in Maize and Simultaneous Study of Their Molecular Recognition Mechanism

“…The FPIA method established by Sheng et al selected the antibody concentration corresponded to 75% fluorescent tracer binding with the best sensitivity ( Sheng et al, 2014 ). In this study, the scFv dilution that corresponded to 70% tracer binding was chosen as the optimum concentration to obtain a wider analytical range according to previous studies ( Deryabina et al, 2005 ). The best antibody dilutions for FB 1 -FITC with 4F5 scFv and 4B9 scFv were 1/30 and 1/700, for FB 1 –5-DTAF with 4F5 scFv and 4B9 scFv were 1/50 and 1/400 in the maize matrix ( Figures 2A,B ).…”

How Does It Work? Case Studies

“…Even small differences in the hapten structure can cause significant changes in the immunoassay characteristics. The fluorescent detection of acetochlor is one example (Deryabina et al 2004). Two haptens obtained by derivatization of the analyte with glycylaminofluorescein and ethylenediaminofluorescein (4.2) showed a remarkable difference in the selectivity and sensitivity of the assay.…”