首页 | 本学科首页   官方微博 | 高级检索  
     检索      


Determining pirimiphos-methyl in durum wheat samples using an acetylcholinesterase inhibition assay
Authors:Email author" target="_blank">Michele?Del CarloEmail author  Alessia?Pepe  Marcello?Mascini  Miriam?De Gregorio  Angelo?Visconti  Dario?Compagnone
Institution:(1) Department of Food Science, University of Teramo, Via Carlo R. Lerici 1, Mosciano Stazione, 64023 Teramo, Italy;(2) Institute of Sciences of Food Production ISPA, CNR, Via Amendola 122/O, 70126 Bari, Italy
Abstract:An electrochemical assay used for detecting acetylcholinesterase (AChE) inhibitors has been optimised to detect pirimiphos-methyl in durum wheat. Pirimiphos-methyl is a phosphothionate insecticide and so it needs to be transformed into the corresponding oxo form to act as an effective AChE inhibitor. The inhibition assay was based on the electrochemical detection of the product of AChE, choline, via choline oxidase biosensors obtained with Prussian-Blue modified screen printed electrodes. The procedure for the oxidation of pirimiphos methyl via N-bromosuccinimide (NBS) and AChE inhibition was optimised for reagent concentrations and inhibition time in a buffer solution. A calibration of the pirimiphos-methyl (25–1,000 ng/ml) was obtained in the buffer. The intra-electrode CV ranged between 1.6 and 15.0, whereas the inter-electrode CV ranged between 4.6 and 16.0. The detection limit (LOD) was 38 ng/ml, and the I50% was 360 ng/ml. The assay conditions were then re-optimised to work with durum wheat extracts, and the calibrations were obtained under different experimental conditions, such as sample pretreatment (milled or whole grains) and extract concentration. The calibrations were slightly affected by the sample matrix, resulting in an increased LOD (65–133 ng/ml) and I50% (640–1,650 ng/ml). The LOD found for the sample, determined under optimal conditions, was 3 mg/kg. Spiked samples were prepared at the EU regulated level (5 mg/kg) and analysed with the optimised protocol, resulting in an average recovery of 70.3%.
Keywords:Pirimiphos-methyl  Whole grain  Acetylcholinesterase inhibition  Choline oxidase biosensor
本文献已被 PubMed SpringerLink 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号