Pérez Emma, Martínez-Peinado Pascual, Marco Francisco, Gras Luis, Sempere José Miguel, Mora Juan, Grindlay Guillermo
Department of Analytical Chemistry, Nutrition and Food Sciences, University of Alicante, PO Box 99, 03080 Alicante, Spain.
Department of Biotechnology, University of Alicante, PO Box 99, 03080 Alicante, Spain.
Food Chem. 2017 Sep 1;230:721-727. doi: 10.1016/j.foodchem.2017.03.078. Epub 2017 Mar 15.
An inductively coupled plasma mass spectrometry (ICP-MS)-based immunoassay has been developed to quantify aflatoxin M1 (AFM1) at ultra-trace levels in milk samples. AFM1 detection is carried out by means of a competitive immunoassay using secondary biotinylated antibodies and streptavidin-conjugated Au nanoparticles. After acid addition, nanoparticles are decomposed and Au signal is registered by means of ICP-MS. Results demonstrate that, under optimum conditions, the limit of detection of the immunoassay (0.005μgkg) is low enough to quantify AFM1 according to current international policies (including the more restrictive European one). Method accuracy and precision was checked by analyzing an AFM1 certified reference material and different milk samples spiked with known amounts of AFM1. AFM1 recovery values range from 80% to 102% whereas inter-assay and intra-assay precision are lower than 15%. Finally, this immunoassay methodology affords a higher dynamic working range (0.012-2.5μgkg) than other immunoassay methodologies described in the literature.
已开发出一种基于电感耦合等离子体质谱（ICP-MS）的免疫分析法，用于定量检测牛奶样品中超痕量水平的黄曲霉毒素M1（AFM1）。AFM1检测通过使用生物素化二抗和链霉亲和素偶联金纳米颗粒的竞争性免疫分析法进行。添加酸后，纳米颗粒分解，通过ICP-MS记录金信号。结果表明，在最佳条件下，免疫分析法的检测限（0.005μg/kg）足够低，能够根据当前国际政策（包括更严格的欧洲政策）对AFM1进行定量。通过分析AFM1认证参考物质和添加已知量AFM1的不同牛奶样品，检验了方法的准确性和精密度。AFM1回收率在80%至102%之间，批间和批内精密度均低于15%。最后，这种免疫分析方法比文献中描述的其他免疫分析方法具有更高的动态工作范围（0.012 - 2.5μg/kg）。
