Niazi Ali, Ghasemi Jahanbakhsh, Yazdanipour Ateesa
Chemistry Department, Faculty of Sciences, Azad University of Arak, Arak, Iran.
Spectrochim Acta A Mol Biomol Spectrosc. 2007 Nov;68(3):523-30. doi: 10.1016/j.saa.2006.12.022. Epub 2006 Dec 22.
Cloud point extraction has been used for the preconcentration of m-nitroaniline, o-nitroaniline and p-nitroaniline and later simultaneous spectrophotometric determination using polyethylene glycol tert-octylphenyl ether (Triton X-100) as surfactant. The resolution of a ternary mixture of the nitroaniline isomers (after extraction by cloud point) by the application of least-squares support vector machines (LS-SVM) was performed. The chemical parameters affecting the separation phase and detection process were studied and optimized. Under the optimum experimental conditions (i.e. pH 7.0, Triton X-100=0.6%, equilibrium time 20 min and cloud point 75 degrees C), calibration graphs were linear in the range of 0.2-20.0, 0.1-15.0 and 0.1-17.0 microg ml(-1) with detection limits of 0.08, 0.05 and 0.06 microg ml(-1) for m-nitroaniline, o-nitroaniline and p-nitroaniline, respectively. The experimental calibration matrix was designed with 21 mixtures of these chemicals. The concentrations were varied between calibration graphs concentrations of nitroaniline isomers. The root mean square error of prediction (RMSEP) for m-nitroaniline, o-nitroaniline and p-nitroaniline were 0.0146, 0.0308 and 0.0304, respectively. This procedure allows the simultaneous determination of nitroaniline isomers in synthetic and real matrix samples good reliability of the determination was proved.
浊点萃取已用于间硝基苯胺、邻硝基苯胺和对硝基苯胺的预富集，随后使用聚乙二醇叔辛基苯基醚（Triton X-100）作为表面活性剂进行同时分光光度法测定。应用最小二乘支持向量机（LS-SVM）对浊点萃取后的硝基苯胺异构体三元混合物进行了分离。研究并优化了影响分离相和检测过程的化学参数。在最佳实验条件下（即pH 7.0、Triton X-100 = 0.6%、平衡时间20分钟和浊点75℃），校准曲线在0.2 - 20.0、0.1 - 15.0和0.1 - 17.0 μg ml⁻¹范围内呈线性，间硝基苯胺、邻硝基苯胺和对硝基苯胺的检测限分别为0.08、0.05和0.06 μg ml⁻¹。实验校准矩阵由这些化学品的21种混合物设计而成。浓度在硝基苯胺异构体校准曲线浓度之间变化。间硝基苯胺、邻硝基苯胺和对硝基苯胺的预测均方根误差（RMSEP）分别为0.0146、0.0308和0.0304。该方法能够同时测定合成样品和实际基质样品中的硝基苯胺异构体，证明了测定具有良好的可靠性。
