Arroyo David, Ortiz M Cruz, Sarabia Luis A, Palacios Francisco
Department of Chemistry, Faculty of Sciences, University of Burgos, Pza. Misael Bañuelos s/n, 09001 Burgos, Spain.
J Chromatogr A. 2009 Jul 17;1216(29):5472-82. doi: 10.1016/j.chroma.2009.05.076. Epub 2009 Jun 2.
This paper reports a multiresponse optimization of an extraction procedure in the simultaneous determination of malachite green (MG) and its metabolite (leucomalachite green, LMG) in fish by liquid chromatography with triple quadrupole mass spectrometry (LC-MS/MS). Prior to optimization, the active factors of the extraction procedure were determined by a screening experimental design. Then, in the optimal experimental conditions of the extraction, MG and LMG have been determined by using a three-way calibration model based on parallel factor analysis (PARAFAC). The procedure fulfils the performance requirements for a confirmatory method established by the European Union Decision 2002/657/EC. This norm establishes maximum permitted tolerances for relative abundance of the precursor/product ion pairs. There is a reported contradiction in the literature related to the fact that there are standard samples whose concentration is greater than CCalpha but the maximum permitted tolerances are not fulfilled in the identification of the analytes. In this work, it is shown that with the information provided by PARAFAC this contradiction is avoided. The figures of merit for PARAFAC and univariate calibration procedures were evaluated under optimal conditions in the extraction step. The figures of merit obtained were in the range of 0.13-0.23 microg kg(-1) for the decision limit, CCalpha, (alpha=0.01) and 0.22-0.39 microg kg(-1) for the detection capability, CCbeta, (beta=0.05), whereas mean relative errors in absolute value were in the range of 2.8-4.6% for MG and LMG with PARAFAC calibration. The proposed optimized extraction procedure using a PARAFAC calibration was also applied in the determination of MG and LMG in gilthead bream samples: the decision limit was in the range of 0.45-0.55 microg kg(-1), the detection capability was in the range of 0.76-0.92 microg kg(-1) for MG and LMG. Trueness was likewise confirmed and the mean of the absolute values of relative errors were between 4.2% and 7.2%.
本文报道了一种采用液相色谱-三重四极杆质谱联用仪（LC-MS/MS）同时测定鱼类中孔雀石绿（MG）及其代谢物隐色孔雀石绿（LMG）的提取方法的多响应优化。在优化之前，通过筛选实验设计确定了提取方法的活性因素。然后，在提取的最佳实验条件下，采用基于平行因子分析（PARAFAC）的三向校准模型测定MG和LMG。该方法满足欧盟第2002/657/EC号决定确立的确证方法的性能要求。该规范规定了前体/产物离子对相对丰度的最大允许公差。文献中报道了一个矛盾，即存在一些标准样品，其浓度大于CCalpha，但在分析物鉴定中未满足最大允许公差。在这项工作中，表明利用PARAFAC提供的信息可以避免这种矛盾。在提取步骤的最佳条件下评估了PARAFAC和单变量校准程序的品质因数。对于决策限CCalpha（α = 0.01），获得的品质因数在0.13 - 0.23 μg kg⁻¹范围内，对于检测能力CCbeta（β = 0.05），在0.22 - 0.39 μg kg⁻¹范围内，而采用PARAFAC校准的MG和LMG的绝对值平均相对误差在2.8 - 4.6%范围内。所提出的采用PARAFAC校准的优化提取方法也应用于金头鲷样品中MG和LMG的测定：MG和LMG的决策限在0.45 - 0.55 μg kg⁻¹范围内，检测能力在0.76 - 0.92 μg kg⁻¹范围内。同样证实了准确性，相对误差绝对值的平均值在4.2%至7.2%之间。
