Abstract
Due to the extensive use of pesticides in agriculture there is an increasing demand for fast performable methods for residue analysis at official food control. This report is concerned with the development of a spectrophotometric enzyme assay in 96-well plate format, with the aim to enable simultaneous screening of multiple samples for organophosphorus and carbamate insecticides by means of their inhibitory effect on cutinase from Fusarium solani pisi. Reaction time of the assay is 30 min. The influence of various solvents on cutinase activity was studied in order to optimize the loss of enzyme activity under organic solvent conditions with respect to pesticide solubility. Methanol concentrations of up to 2.5% in the inhibition batch exhibit negligible influence on cutinase activity. Aqueous mixtures of 10% methanol and 40% diethylene glycol are advantageously bridging restricted pesticide solubility with maintenance of enzyme activity. The detection limit of paraoxon, a potent cutinase inhibitor with an inhibitory rate constant of 1.6×104 L/(mol min), was determined to 0.04 mg/L. For chlorpyrifos, the most often detected pesticide on fruit and vegetables, the detection limit was 2.6 mg/L with an inhibition constant of 2.0×103 L/(mol min). Working principle and efficiency of the assay are discussed in detail in terms of enzyme kinetics.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
