Hoshi University, Faculty of Pharmaceutical Sciences, Department of Analytical Chemistry, 2-4-41, Ebara, Shinagawa-ku, Tokyo 142-8501, Japan.
Saitama Institute of Public Health, Saitama, Japan.
J AOAC Int. 2020 Nov 1;103(6):1521-1527. doi: 10.1093/jaoacint/qsaa077.
Aflatoxins (AFs) are carcinogenic mycotoxins. A simple, quick, and accurate method for the micro-analysis of AFs in foodstuffs, especially spices, is needed.
A sophisticated pretreatment method that combines solid-phase dispersive extraction (SPDE) and solid-phase fluorescence derivatization using immunoaffinity (IA) gel as the solid phase was developed to analyze AFs in spices simply, quickly, and sensitively by liquid chromatography with fluorescence detection.
White and black pepper samples were extracted with a mixed solution of methanol/water (4:1) and then diluted with 7% aqueous solution of Triton-X. The solution was subjected to cleanup by SPDE using IA gel. Trifluoroacetic acid was added to the IA gel for on-site solid-phase fluorescence derivatization.
Chromatograms containing well-separated peaks and few interference peaks from contaminants were obtained. The method detection limit of AFs in white and black pepper was 0.15-0.29 ng/g. Repeatability and intermediate precision were <10% and <15%, respectively, and accuracy was 61.7-87.8%. In addition, inter-laboratory precision was <29% and mean recovery was 61.5-76.7%. A favorable z-score of |Z| ≦ 1 was obtained in seven laboratories, although one laboratory gave 2 < |Z| < 3.
The validity, reliability, practicality, and robustness of the developed method were verified.
By using SPDE and solid-phase fluorescence derivatization in combination for AF analysis, fluorescence derivatization during cleanup was realized, leading to simplification of the pretreatment operation.
黄曲霉毒素（AFs）是致癌的真菌毒素。需要一种简单、快速、准确的方法来检测食品，尤其是香料中的黄曲霉毒素。
建立了一种复杂的预处理方法，该方法结合了固相分散萃取（SPDE）和固相荧光衍生化，使用免疫亲和（IA）凝胶作为固相，通过液相色谱-荧光检测简单、快速、灵敏地分析香料中的黄曲霉毒素。
用甲醇/水（4:1）混合溶液提取白胡椒和黑胡椒样品，然后用 7% Triton-X 水溶液稀释。用 IA 凝胶通过 SPDE 进行净化。在 IA 凝胶中加入三氟乙酸进行现场固相荧光衍生化。
得到了包含分离良好的峰和来自污染物的少量干扰峰的色谱图。白胡椒和黑胡椒中黄曲霉毒素的方法检测限为 0.15-0.29 ng/g。重复性和中间精密度分别<10%和<15%，准确性为 61.7-87.8%。此外，实验室间精密度<29%，平均回收率为 61.5-76.7%。在七个实验室中，得到了有利的 Z 值 |Z|≦1，尽管一个实验室得到了 2<|Z|<3。
验证了所开发方法的有效性、可靠性、实用性和稳健性。
通过将 SPDE 和固相荧光衍生化结合起来分析 AF，在净化过程中实现了荧光衍生化，从而简化了预处理操作。
