Zhou Tingting, Liu Yuanxi, Xie Xuan, Wang Dandan, Jin Hongyu, Wei Feng, Wang Miao, Wang Ying
Objective: To study the application effects of acetamiprid colloidal gold immunochromatographic test strips from different brands in the matrix of Lycii Fructus, optimize the pre-treatment conditions for Lycii Fructus, and establish a rapid colloidal gold immunochromatographic detection method for acetamiprid in Lycii Fructus. Methods: The detection limits, specificity, sensitivity, false positive and false negative rates of three different brands of colloidal gold immunochromatography test strips in the matrix of Lycii Fructus were examined. The pretreatment conditions for Lycii Fructus, including herbal medicine forms, extraction solvents, extraction solvents volume and dilution ratios were optimized, and the performance of the optimized method was evaluated. Results: The detection limits of the three brands of acetamiprid colloidal gold test strips in the matrix of Lycii Fructus were 0.25, 0.50, and 0.50 mg · kg-1, respectively. The results of specificity and cross reactivity were all negative, with a false negative rate of 0%, but the false positive rate was 50%. The optimal pretreatment conditions for Lycii Fructus involve extracting (1.00±0.05) g of ground sample using 4 mL of 0.01 mol·L-1 phosphate-buffered saline (PBS). After centrifugation, 20 μL of the supernatant was diluted with 980 μL of the extraction solvent to obtain the test solution. The performance evaluation results were satisfactory. Conclusion: The colloidal gold immunochromatography method has the advantages of simplicity and rapidity in the detection of acetamiprid pesticide residues, but there are generally high false positive rates in the detection of Lycii Fructus matrices. The rapid colloidal gold immunochromatography detection method established by optimizing pretreatment conditions in this study for acetamiprid in Lycii Fructus resolved the problem of false positive, and had the advantages of accurate and reliable determination results and simplicity in operation. It is suitable for on-site rapid detection of acetamiprid in Lycii Fructus, providing technical support for the quality and safety supervision of Lycii Fructus, as well as providing a technical reference for the application of colloidal gold immunochromatography in the rapid detection of pesticide residues in traditional Chinese medicine.