酶抑制-数字图像比色法检测和鉴别食品中二硫代氨基甲酸酯、氨基甲酸酯和有机磷类农药残留

目的 建立一种酶抑制-数字图像比色法检测和鉴别食品中二硫代氨基甲酸酯、氨基甲酸酯和有机磷类农药残留的分析方法。方法 采用简单的胶带黏贴剥离方式,结合低共熔溶剂洗脱对食品样品中的农药进行高效提取。基于二硫代氨基甲酸酯、氨基甲酸酯和有机磷类农药对酪氨酸酶的抑制活性,使酪氨酸酶对酚类物质的氧化能力降低,进而影响酚类物质与氯化铁生成有色物质的反应,建立酪氨酸酶、酚类物质和氯化铁的比色阵列传感器,实现农药的残留分析,并结合主成分分析实现多种农药的区分。结果 本研究建立的酶抑制-数字图像比色法对番茄、苹果和玉米中福美锌残留在0.008～8.000mg/kg的范围内线性良好,检出限为0.003 mg/kg,定量限为0.008 mg/kg,回收率为75.2%～94.9%,相对标准偏差小于5.0%。结论 本研究建立的酶抑制-数字图像比色法绿色环保、简单高效,且易于推广,适用于蔬菜、水果和谷物等食品样品中农药残留的检测,并且在多种农药的残留分析方面有良好的应用前景。

Detection and identification of dithiocarbamate, carbamate, and organophosphorus pesticide residues in food by enzyme inhibition-digital image colorimetry

Objective To establish a green, efficient, and convenient analytical method for the detection and identification of dithiocarbamate, carbamate, and organophosphorus pesticide residues in vegetables, fruits, and cereal. Methods The efficient extraction of pesticides was conducted through the utilization of simple adhesive tape pasting and stripping, followed by deep eutectic solvent elution. Dithiocarbamate, carbamate, and organophosphorus pesticides can inhibit the activity of tyrosinase and reduce the ability of tyrosinase to oxidize phenolics and affected the reaction between phenolics and ferric chloride to produce colored substances, which realizeed the analysis of pesticide residues. By establishing the colorimetric array sensor of tyrosinase, phenolic substances (catechol, pyrogallol, and 4-aminophenol), and ferric chloride, the principal component analysis realized the distinction of multiple pesticides (ziram, ferbam, thiram, carbofuran, carbaryl, glyphosate, and acephate). Results The enzyme inhibition combined with the digital image colorimetry method established in this study had a good linear effect on the residues of zinc in tomato, apple, and corn in the range of 0.008-8.000 mg kg-1, the limit of detection was 0.003 mg kg-1, and the limit of quantification was 0.008 mg kg-1. The recoveries ranged from 75.2% to 94.9% with relative standard deviations less than 5.0%. Conclusion The enzyme inhibition combined with the digital image colorimetry method established in this study is environmentally friendly, simple and efficient, and easy to popularize, which is suitable for the detection of pesticide residues in food samples such as vegetables, fruits, and grains, and has a good application in the analysis of multiple pesticide residues.