Dipartimento di Scienze Farmaceutiche e Biomediche, Università degli Studi di Salerno, via Ponte Don Melillo, 84084 Fisciano (SA), Italy.
J Chromatogr A. 2011 Oct 21;1218(42):7648-54. doi: 10.1016/j.chroma.2011.05.028. Epub 2011 May 14.
The application of dispersive liquid-liquid microextraction (DLLME) technique for the rapid analysis of aflatoxins B(1), B(2), G(1) and G(2) in maize, rice and wheat products has been evaluated. After extraction of aflatoxins from cereal matrices with a mixture of methanol/water 8:2 (v/v), the analytes were rapidly transferred from the extract to another small volume of organic solvent, chloroform, by DLLME. Aflatoxins were determined using high performance liquid chromatography with florescence detection and photochemical post-column derivatization. Parameters affecting both extraction and DLLME procedures, such as extraction solvent, type and volume of DLLME extractant, volume of water and salt effect, were systematically investigated and optimized to achieve the best extraction efficiency. Under the optimal experimental conditions, the whole analytical method provides enrichment factors around 2.5 times and detection limits (0.01-0.17 μg kg(-1)) below the maximum levels imposed by current regulation for aflatoxins in cereals and cereal products intended for direct human consumption. Recoveries (67-92%) and repeatability (RSD<10, n=3), tested in three different cereal matrices, meet the performance criteria required by EC Regulation No. 401/2006 for the determination of the levels of mycotoxins in foodstuffs. The proposed method was successfully applied to the analysis of retail cereal products with quantitative results comparable to the immunoaffinity chromatography (IAC). The main advantages of developed method are the simplicity of operation, the rapidity to achieve a very high sample throughput and low cost.
分散液相微萃取（DLLME）技术在快速分析玉米、大米和小麦产品中的黄曲霉毒素 B(1)、B(2)、G(1)和 G(2)方面的应用已经得到了评估。用甲醇/水 8:2（v/v）的混合物从谷物基质中提取黄曲霉毒素后，通过 DLLME 将分析物迅速从提取物转移到另一种小体积有机溶剂——氯仿中。采用高效液相色谱法和荧光检测以及光化学柱后衍生化法测定黄曲霉毒素。系统地考察和优化了影响萃取和 DLLME 过程的参数，如萃取溶剂、DLLME 萃取剂的类型和体积、水的体积和盐效应等，以达到最佳的萃取效率。在最佳实验条件下，整个分析方法提供了约 2.5 倍的富集因子和检测限（0.01-0.17μgkg(-1)），低于当前法规对人类直接食用的谷物和谷物产品中黄曲霉毒素的最大限量。在三种不同的谷物基质中测试的回收率（67-92%）和重复性（RSD<10，n=3）满足 EC 法规 No.401/2006 对食品中霉菌毒素水平测定的性能要求。该方法已成功应用于零售谷物产品的分析，定量结果与免疫亲和色谱（IAC）相当。所开发方法的主要优点是操作简单、快速实现非常高的样品通量和低成本。
