Bautista-Flores Ana Nelly, De San Miguel Eduardo Rodríguez, Gyves Josefina de, Jönsson Jan Åke
Química Industrial, Universidad Tecnológica del Sureste de Veracruz, Av. Universidad Tecnológica Lote Grande #1, Nanchital 93770, Veracruz, Mexico.
Departamento de Química Analítica, Facultad de Química, UNAM, Ciudad Universitaria, México 04510, D.F., Mexico.
Membranes (Basel). 2011 Aug 18;1(3):217-31. doi: 10.3390/membranes1030217.
Nickel (II) preconcentration and speciation analysis using a hollow fiber supported liquid membrane (HFSLM) device was studied. A counterflow of protons coupled to complexation with formate provided the driving force of the process, while Kelex 100 was employed as carrier. The influence of variables related to module configuration (acceptor pH and carrier concentration) and to the sample properties (donor pH) on the preconcentration factor, E, was simultaneously studied and optimized using a 3 factor Doehlert matrix response surface methodology. The effect of metal concentration was studied as well. Preconcentration factors as high as 4240 were observed depending on the values of the different variables. The effects of the presence of inorganic anions (NO2-, SO42-, Cl-, NO3-, CO32-, CN-) and dissolved organic matter (DOM) in the form of humic acids were additionally considered in order to carry out a speciation analysis study. Nickel preconcentration was observed to be independent of both effects, except when cyanide was present in the donor phase. A characterization of the transport regime was performed through the analysis of the dependence of E on the temperature. E increases with the increase in temperature according to the equation E(K) = -8617.3 + 30.5T with an activation energy of 56.7 kJ mol-1 suggesting a kinetic-controlled regime. Sample depletion ranged from 12 to 1.2% depending on the volume of the donor phase (100 to 1000 mL, respectively).
研究了使用中空纤维支撑液膜（HFSLM）装置进行镍（II）预富集和形态分析。质子的逆流与甲酸盐络合提供了该过程的驱动力，同时使用Kelex 100作为载体。使用三因素Doehlert矩阵响应面方法同时研究并优化了与模块配置（受体pH值和载体浓度）以及样品性质（供体pH值）相关的变量对预富集因子E的影响。还研究了金属浓度的影响。根据不同变量的值，观察到预富集因子高达4240。为了进行形态分析研究，还额外考虑了无机阴离子（NO2-、SO42-、Cl-、NO3-、CO32-、CN-）的存在以及腐殖酸形式的溶解有机物（DOM）的影响。观察到镍的预富集与这两种影响均无关，除非供体相中存在氰化物。通过分析E对温度的依赖性来表征传输机制。根据方程E(K)= -8617.3 + 30.5T，E随温度升高而增加，活化能为56.7 kJ mol-1，表明是动力学控制机制。根据供体相的体积（分别为100至1000 mL），样品消耗范围为12%至1.2%。
