Department of Food Science, University of Teramo, Via Carlo R. Lerici 1, Mosciano Stazione, 64023 Teramo, Italy.
Talanta. 2010 Apr 15;81(1-2):76-81. doi: 10.1016/j.talanta.2009.11.038. Epub 2010 Jan 22.
An analytical protocol based on an electrochemical assay for the detection of acetylcholinesterase (AChE) inhibitors has been optimised for the detection of coumaphos in honey. Coumaphos is a phosphotionate insecticide requiring transformation in 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 a choline oxidase biosensors obtained using prussian-blue modified screen printed electrodes. A simple procedure for the oxidation of coumaphos via N-bromosuccinimide (NBS) and AChE inhibition was optimised. A calibration curve for coumaphos (8-1000 ng/ml) was obtained in buffer; the intra electrode CV ranged between 8 and 12% whereas the inter electrode CV was comprised between 12 and 14%. A detection limit (LOD) of 8 ng/ml was achieved, with an I(50%) of 105 ng/ml. The assay was then applied to detect coumaphos in honey samples. Despite the solubility of the samples in buffer, the assay was affected by many electrochemical interferences present in this sample matrix A simple C18 based solid phase extraction procedure has been then optimised and used for the assay. This allowed to eliminate all the electrochemical interferences with a satisfactory coumaphos recovery (around 86%) for a final LOD of 33 ng/g. The developed assay applied to detect coumaphos in different honey samples gave data well correlated with LC-MS detection.
一种基于电化学分析方法检测乙酰胆碱酯酶（AChE）抑制剂的分析方案已经过优化，可用于检测蜂蜜中的保棉磷。保棉磷是一种需要转化为相应的氧代形式才能作为有效 AChE 抑制剂的膦酸盐杀虫剂。抑制分析基于通过使用普鲁士蓝修饰的丝网印刷电极获得的胆碱氧化酶生物传感器电化学检测 AChE 的产物胆碱。通过 N-溴代丁二酰亚胺（NBS）和 AChE 抑制对保棉磷进行简单的氧化优化。在缓冲液中获得了保棉磷（8-1000ng/ml）的校准曲线；电极内 CV 在 8-12%之间，而电极间 CV 在 12-14%之间。实现了 8ng/ml 的检测限（LOD），I（50%）为 105ng/ml。然后将该测定法应用于检测蜂蜜中的保棉磷。尽管样品在缓冲液中的溶解度，但该测定受到该样品基质中存在的许多电化学干扰的影响。然后优化并使用了一种基于 C18 的简单固相萃取程序进行测定。这允许消除所有电化学干扰，并获得令人满意的保棉磷回收率（约 86%），最终 LOD 为 33ng/g。应用于检测不同蜂蜜样品中保棉磷的开发测定法与 LC-MS 检测数据相关性良好。
