Determination of metolcarb in food by capillary electrophoresis immunoassay with a laser-induced fluorescence detector.
A capillary electrophoresis immunoassay (CEIA) was developed for the determination of trace metolcarb (MTMC) in food. The method was based on the competitive reactions between fluorescently labeled MTMC tracer and free MTMC with a limited amount of anti-MTMC antibody and the separation and determination by CE with LIF detector. A fluorescent reagent, FITC was labeled on MTMC to construct an immunofluorescent probe. CEIA experimental parameters such as the pH value and concentration of the running buffer and separation voltage as well as incubation time were systematically investigated. Under the optimized conditions, fluorescently labeled antigen and antibody bound could be well separated within 3 min using Na₂B₄O₇/NaH₂PO₄ buffer (20:10 mmol/L, pH 9.0) for background electrolyte, 20 kV for the separation voltage, and 20°C for the column temperature. The linear range of the method was 0.25-50.0 μg/L with LOD 0.07 μg/L. The RSD for relative migration time and relative fluorescence intensity ratio were 2.90% (intraday) and 4.73% (intraday), respectively. The proposed method has been applied to determine the residue of MTMC in food samples with the satisfactory recovery.
Key Laboratory of Food Nutrition and Safety, Ministry of Education, Tianjin Key Laboratory of Food Nutrition and Safety, Tianjin University of Science and Technology, Tianjin, China.
Cuicui
C
Liu
Guozhen
G
Fang
Qiliang
Q
Deng
Yan
Y
Zhang
Jingjing
J
Feng
Shuo
S
Wang
D000818:Animals; D000906:Antibodies; D018553:Cucumis sativus / Q000737:chemistry; D019075:Electrophoresis, Capillary / Q000379:methods*; D005260:Female; D005504:Food Analysis / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D007118:Immunoassay / Q000379:methods*; D057230:Limit of Detection; D012275:Oryza / Q000737:chemistry; D010573:Pesticide Residues / Q000032:analysis*; D048448:Phenylcarbamates / Q000032:analysis*; D011817:Rabbits; D015203:Reproducibility of Results; D013050:Spectrometry, Fluorescence
D000906:Antibodies; D010573:Pesticide Residues; D048448:Phenylcarbamates; C532346:metolcarb