A novel colloidal gold-based lateral flow immunoassay for rapid simultaneous detection of cyromazine and melamine in foods of animal origin

• Published in: Food chemistry 2013-06, Vol.138 (2-3), p.1610-1615
• Main Authors: Le, Tao, Yan, Peifeng, Xu, Jian, Hao, Youjing
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Cattle; Chickens; Colloidal gold; Cyromazine; Food Contamination - analysis; Food industries; Food-producing animals; Fundamental and applied biological sciences. Psychology; General aspects; Gold Colloid - chemistry; Immunoassay - instrumentation; Immunoassay - methods; Lateral-flow strip assay; Limit of Detection; Liver - chemistry; Meat - analysis; Melamine; Methods of analysis, processing and quality control, regulation, standards; Milk - chemistry; Pesticides - analysis; Sheep; Swine; Triazines - analysis
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2012.11.077

► This is the first report of test strip for the rapid simultaneous detection of cyromazine and melamine in foods. ► Good correlations of the results obtained by the test strip and HPLC. ► we presented the preparation of the specific and bispecific monoclonal antibody of CA or MA. A rapid and sensitive lateral flow immunoassay (LFIA) based on competitive format was developed and validated for simultaneous detection of cyromazine (CA) and melamine (MA) in foods of animal origin. With this method, the cut-off value for the two test lines were achieved at 25ng/g, which was lower than the maximum residue levels (MRLs) established for CA and MA. At three fortified levels (50, 100, and 150ng/g), the recoveries for CA and MA ranged from 73.9% to 104.2% with the relative standard deviation (RSD) less than 11.9%, based on within day and interday analysis. The lower detection limit for CA and MA in matrix sample were 0.22ng/ml and 0.26ng/ml, respectively, which were lower than those of published literatures. A parallel analysis of CA and MA in real samples conducted by HPLC showed comparable results to those obtained from LFIA. The results of LFIA were in good agreement with those of high performance liquid chromatography (HPLC) in the analysis of CA and MA in foods of animal origin, demonstrating the practical applicability of the developed assay in real samples. Overall, to our knowledge, this is the first report of quantitative or semi-quantitative simultaneous detection for CA and MA by immunochromatographic assay.