Medina Angel, Jiménez Misericordia, Gimeno-Adelantado José V, Valle-Algarra Francisco M, Mateo Rufino
Departamento de Microbiología y Ecología, Facultad de Biología, Universitat de Valencia, Dr. Moliner 50, E-46100 Burjassot, Valencia, Spain.
J Chromatogr A. 2005 Aug 12;1083(1-2):7-13. doi: 10.1016/j.chroma.2005.05.089.
A new sample treatment for liquid chromatographic analysis of ochratoxin A (OTA) in beer is proposed. Degassed beer is mixed with lead hydroxyacetate, which precipitates some bulk components but does not remove OTA. The precipitate is separated and the acidified liquid is extracted with chloroform. The solvent is evaporated and the residue is dissolved in mobile phase (acetonitrile-water, 40:60, v/v; acidified at pH 3.0 with phosphoric acid) and separated by liquid chromatography using fluorescence detection. The limit of detection was 0.005 ng/ml. The average recovery rate and the average RSD of recovery in the spiking level range 0.01-0.5 ng/ml were 95.5% and about 5%, respectively. The method is cheaper that other alternative ones using immunoaffinity columns or other solid-phase extraction cleanup:The separation was optimised with regard to composition and flow of the mobile phase and no interference from the matrix was found. The method was applied to 88 samples of beer (domestic and imported) marketed in Spain. OTA was detected in 82.9% of them. The range for positive samples was 0.007-0.204 ng of OTA/ml.
本文提出了一种用于啤酒中赭曲霉毒素A（OTA）液相色谱分析的新型样品处理方法。将脱气后的啤酒与羟基乙酸铅混合，该试剂可沉淀一些主要成分，但不会去除OTA。分离沉淀后，用氯仿萃取酸化后的液体。蒸发溶剂，将残留物溶解于流动相（乙腈 - 水，40:60，v/v；用磷酸酸化至pH 3.0）中，并通过荧光检测的液相色谱法进行分离。检测限为0.005 ng/ml。在0.01 - 0.5 ng/ml的加标水平范围内，平均回收率和回收率的平均相对标准偏差分别为95.5%和约5%。该方法比其他使用免疫亲和柱或其他固相萃取净化的替代方法成本更低：对流动相的组成和流速进行了优化分离，未发现基质干扰。该方法应用于西班牙市场上销售的88个啤酒样品（国产和进口）。其中82.9%检测到OTA。阳性样品中OTA的含量范围为0.007 - 0.204 ng/ml。
