Application of fluorescence polarization immunoassay for acetochlor determination in medicinal plant material

Introduction. Acetochlor is one of the most common herbicides capable of accumulating in medicinal plant raw materials and posing a health risk. A method for acetochlor determination was developed using fluorescence polarization immunoassay (FPIA), a homogeneous and specific technique employed for analysis of low-molecular-weight toxicants. Aim. To develop and validate a fluorescence polarization immunoassay for quantitative analysis of the herbicide acetochlor in medicinal plant material, exemplified by corn silk ( Zea mays L.). Materials and methods. For the development of the method, polyclonal rabbit antibodies against acetochlor and a tracer consisting of an acetochlor derivative conjugated with ethylenediamine fluorescein (AMPA-EDF) were used. The analysis was performed by fluorescence polarization using a portable Sentry-200 fluorimeter (Ellie LLC, USA). Data processing was carried out with SigmaPlot 11 software package (Systat Software Inc., USA). The study was performed on samples of corn silk medicinal plant material purchased from a local pharmacy and an online store. Method validation included the following parameters: limit of detection, limit of quantification, analytical range, precision, accuracy, and specificity. Results and discussion. A method for the quantitative determination of the pesticide acetochlor in the herbal medicinal raw material corn silk ( Zea mays L.) has been developed, optimized, and validated using fluorescence polarization immunoassay (FPIA). The determination range was from 0.024 to 1.56 mg/kg. The specificity, precision, and accuracy of the developed method were confirmed. Conclusion. The fluorescence polarization immunoassay (FPIA) method was applied for the quantitative determination of the pesticide acetochlor in herbal medicinal raw material, using corn silk as an example.