Meloun Milan, Syrový Tomás
Department of Analytical Chemistry, Faculty of Chemical Technology, University of Pardubice, CZ-532 10 Pardubice, Czech Republic.
Talanta. 2007 Jan 15;71(1):115-22. doi: 10.1016/j.talanta.2006.03.035. Epub 2006 May 9.
A critical comparison of the selected derivative principal component analysis (PCA) methods on the absorbance matrix data concerning the complexation equilibria between o-CAPAZOXS and Cd(2+), Pb(2+) and Zn(2+) or m-CAPAZOXS and Cd(2+), Co(2+), Ni(2+) and Zn(2+) or p-CAPAZOXS and Cd(2+) and Zn(2+) at 25 degrees C is provided. As the number of complex species in a complex-forming equilibria mixture is an important step in spectral data treatment, the nine selected index functions for the prediction of the number of light-absorbing species that contribute to a set of spectra is critically tested by the PCA. An improved identification with the second SD(AE) or third derivative TD(AE) and derivative ratio function ROD(AE) for the average error criterion AE is preferred. After the number of various complexes formed the stability constants of species ML, ML(2) (and ML(3), respectively) type log beta(11), log beta(12) (and log beta(13), respectively) for the system of o-CAPAZOXS (ligand L) with the metals (the standard deviation s(log beta(pq)) of the last valid digits is given in brackets) Cd(2+) (6.39(5) and 11.51(9)), Pb(2+) (4.24(2) and 9.01(2)) and Zn(2+) (5.18(7) and 9.06(10)) and for the system of m-CAPAZOXS with Cd(2+) (6.59(20) and 11.51(32)), Co(2+) (7.19(6) and 12.19(8)), Ni(2+) (7.64(7) and 13.39(12)) and Zn(2+) (4.83(3) and 9.57(3)) and for the system of p-CAPAZOXS with Cd(2+) (6.44(5), 10.99(10) and 14.57(25)) and Zn(2+) (6.84(16), 13.05(29) and 18.74(43)) at 25 degrees C are estimated using SQUAD(84) nonlinear regression of the mole-ratio spectrophotometric data. The computational strategy is presented with goodness-of-fit tests and various regression diagnostics capable of proving the reliability of the chemical model proposed.
本文对选定的衍生主成分分析（PCA）方法进行了关键比较，该方法用于处理邻 - CAPAZOXS与Cd(2+)、Pb(2+)和Zn(2+)，间 - CAPAZOXS与Cd(2+)、Co(2+)、Ni(2+)和Zn(2+)，对 - CAPAZOXS与Cd(2+)和Zn(2+)在25℃下形成配合物平衡的吸光度矩阵数据。由于形成配合物平衡混合物中配合物种类的数量是光谱数据处理的重要步骤，因此PCA对用于预测一组光谱中吸光物种数量的九个选定指标函数进行了严格测试。对于平均误差标准AE，采用二阶SD(AE)或三阶导数TD(AE)以及导数比函数ROD(AE)可实现更好的识别。在确定各种形成的配合物数量后，使用SQUAD(84)对摩尔比分光光度数据进行非线性回归，估计邻 - CAPAZOXS（配体L）与金属（括号内给出最后有效数字的标准偏差s(logβ(pq))）体系中物种ML、ML₂（分别还有ML₃）类型的logβ₁₁、logβ₁₂（分别还有logβ₁₃）的稳定常数，其中Cd(2+)（6.39(5)和11.51(9)）、Pb(2+)（4.24(2)和9.01(2)）、Zn(2+)（5.18(7)和9.06(10)）；间 - CAPAZOXS与Cd(2+)（6.59(20)和11.51(32)）、Co(2+)（7.19(6)和12.19(8)）、Ni(2+)（7.64(7)和13.39(12)）、Zn(2+)（4.83(3)和9.57(3)）；对 - CAPAZOXS与Cd(2+)（6.44(5)、10.99(10)和14.57(25)）、Zn(2+)（6.84(16)、13.05(29)和18.74(43)）在25℃下的稳定常数。本文还介绍了计算策略，并通过拟合优度检验和各种回归诊断方法来证明所提出化学模型的可靠性。
