Chemistry and Chemical Engineering Research Center of Iran, P.O. Box 14335-186, Pazhoohesh St., Vardavard, Tehran, Iran.
Anal Chim Acta. 2010 Mar 17;663(1):11-8. doi: 10.1016/j.aca.2010.01.039. Epub 2010 Feb 1.
In the present study a second-order calibration strategy for high performance liquid chromatography with diode-array detection (HPLC-DAD) has been developed using parallel factor analysis (PARAFAC) and has been applied for simultaneous determination of aflatoxins B(1), B(2), G(1) and G(2) in pistachio nuts in the presence of matrix interferences. Sample preparation was based on solvent extraction (SE) followed by solid phase extraction (SPE) on Bond Elut C18 cartridges. Since the sample preparation procedure was not selective to the analytes of interest, exploiting second-order advantage to obtain concentrations of individual analytes in the presence of uncalibrated interfering compounds seemed necessary. Appropriate pre-processing steps have been applied to correct background signals and the effect of retention time shifts. Transferred calibration data set obtained from standardization of solvent based calibration data has been used in prediction step. The results of PARAFAC on a set of spiked and naturally contaminated pistachio nuts indicated that the four aflatoxins could be successfully determined. The method was validated and multivariate analytical figures of merit were calculated. The advantages of the proposed method are using a low-cost SPE step relative to standard method of aflatoxin analysis (immune affinity column assay), a unique and simple isocratic elution program for all samples and a calibration transfer for saving both chemicals and time of analysis. This study show that coupling of SPE-HPLC-DAD with PARAFAC as a powerful second-order calibration method can be considered as an alternative method for resolution and quantification of aflatoxins in the presence of unknown interferences obtained through analysis of highly complex matrix of pistachio samples and cost per analysis can be reduced significantly.
在本研究中，采用平行因子分析（PARAFAC）开发了一种用于高效液相色谱二极管阵列检测（HPLC-DAD）的二阶校准策略，并将其应用于同时测定存在基质干扰的开心果中黄曲霉毒素 B(1)、B(2)、G(1)和 G(2)。样品制备基于溶剂萃取（SE），然后在 Bond Elut C18 小柱上进行固相萃取（SPE）。由于样品制备程序对感兴趣的分析物没有选择性，因此似乎有必要利用二阶优势在未校准干扰化合物存在的情况下获得单个分析物的浓度。已经应用了适当的预处理步骤来校正背景信号和保留时间偏移的影响。从基于溶剂的校准数据的标准化获得的转移校准数据集已用于预测步骤。PARAFAC 在一组加标和天然污染的开心果上的结果表明，可以成功地测定四种黄曲霉毒素。该方法已得到验证，并计算了多维分析的重要指标。该方法的优点是相对于黄曲霉毒素分析的标准方法（免疫亲和柱测定法）使用低成本 SPE 步骤、所有样品的独特且简单的等度洗脱程序以及校准转移，以节省分析的化学物质和时间。这项研究表明，SPE-HPLC-DAD 与 PARAFAC 耦合作为一种强大的二阶校准方法，可以被认为是解决和定量存在未知干扰的黄曲霉毒素的替代方法，通过分析复杂的开心果样品基质获得，并且可以显著降低分析成本。
