Sombra L, Luconi M, Silva M F, Olsina R A, Fernandez L
Area of Analytical Chemistry, National University of San Luis, Chacabuco y Pedernera, Argentina.
Analyst. 2001 Jul;126(7):1172-6. doi: 10.1039/b009251g.
A cloud point preconcentration and flow injection (FI) analysis methodology for aluminium(III) determination has been developed. The analyte in the initial aqueous solution was complexed with Chrome Azurol S (CAS) in the presence of the cationic surfactant benzyldimethyltetradecylammonium chloride (BDTAC). The absorption spectroscopic characteristics of the ternary complex [Al(III)-CAS-BDTAC] were examined in detail. The preconcentration step was carried out by means of the non-ionic surfactant polyethylene glycol p-nonylphenyl ether (PONPE 7.5). The enriched analyte solution was injected into an FI system using an HPLC pump. The chemical variables affecting the analytical performance of the combined methodology were studied and optimised. The developed approach was successfully applied to the determination of trace amounts of aluminium in parenteral solutions without previous treatment. Under the optimum experimental conditions, 99.9% extraction was achieved for a preconcentration factor of 50. The limit of detection was 1.12 x 10(-7) mol(-1). The calibration plot was linear over at least two orders of magnitude of aluminium concentration. The developed coupled methodology, which thoroughly satisfies the typical requirements for pharmaceutical control processes, is appropriate for monitoring the aluminium concentration in parenteral nutrition.
已开发出一种用于测定铝（III）的浊点预富集和流动注射（FI）分析方法。初始水溶液中的分析物在阳离子表面活性剂苄基二甲基十四烷基氯化铵（BDTAC）存在下与铬天青S（CAS）络合。详细研究了三元络合物[Al（III）-CAS-BDTAC]的吸收光谱特性。预富集步骤通过非离子表面活性剂聚乙二醇对壬基苯基醚（PONPE 7.5）进行。使用高效液相色谱泵将富集的分析物溶液注入FI系统。研究并优化了影响该组合方法分析性能的化学变量。所开发的方法成功应用于不经预处理测定注射用溶液中的痕量铝。在最佳实验条件下，预富集因子为50时，萃取率达到99.9%。检测限为1.12×10⁻⁷ mol⁻¹。校准曲线在至少两个数量级的铝浓度范围内呈线性。所开发的联用方法完全满足药物控制过程的典型要求，适用于监测肠外营养中的铝浓度。
