T/CAICC 02-2021 The rapid detection of imidacloprid in raw milk using colloidal gold immunochromatography method
T/CAICC 02-2021 The rapid detection of imidacloprid in raw milk using colloidal gold immunochromatography method
Basic Information
Scope
Scope: This method specifies a rapid detection method for chlorpyrifos in raw milk using colloidal gold immunoassay. This method is suitable for the rapid determination of chlorpyrifos in raw milk; Main technical content: 3 Principles This method adopts the principle of competitive inhibition immunoassay. After extraction, chlorpyrifos in the sample combines with the colloidal gold-labeled specific antibody, inhibiting the binding of the antibody and the antigen on the detection line (T line) of the test strip, resulting in a change in the color depth of the detection line. By comparing the color depth of the detection line with that of the control line (C line), the qualitative determination of chlorpyrifos in the sample is carried out. 4 Reagents and materials 4.1 Reagents Unless otherwise specified, all reagents are of analytical purity, and the laboratory water should meet the requirements of Class II water in GB/T 6682. 4.1.1 Methanol (CH3OH). 4.1.2 Reference substances: The Chinese and English names, CAS registry number, molecular formula, and relative molecular mass of the chlorpyrifos reference substance are shown in Table 1. The purity should be ≥98%. Table 1 Chinese and English names, CAS registry number, molecular formula, and relative molecular mass of the chlorpyrifos reference substance Chinese name English name CAS registry number Molecular formula Relative molecular mass Chlorpyrifos Acetamiprid 160430-64-8 C10H11ClN4 222.68 Note: Equivalent traceable substances may also be used. 4.2 Solution preparation 4.2.1 Chlorpyrifos standard stock solution (100 μg/mL): Accurately weigh 1 mg of the chlorpyrifos reference substance (4.1.2) and place it in a 10 mL volumetric flask. Dissolve and dilute to the mark with methanol (4.1.1), shake well, and prepare a chlorpyrifos standard stock solution with a concentration of 100 μg/mL. Store at 4°C in the dark for 6 months. 4.2.2 Chlorpyrifos standard working solution (1 μg