Laboratory of Analytical Chemistry, Department of Chemistry, University of Ioannina, 45110 Ioannina, Greece.
Talanta. 2010 Mar 15;80(5):2049-56. doi: 10.1016/j.talanta.2009.11.003. Epub 2009 Nov 10.
In this work, a rapid assay of water hardness is presented based on the formation of a coacervate phase made up of multilamellar vesicles and close bilayers produced upon the reaction of alkaline earth metals with a carboxylate anionic surfactant in the presence of a co-surfactant (methanol). The procedure exploits the light scattering abilities of the coacervate phase which can be logarithmically linked to total hardness as CaCO(3) equivalents via spectrophotometric detection at 350 nm. The method, abbreviated as HALC, stemming from hardness by alkaline earth metal coacervation, is straightforwardly applicable overcoming the requirement for regulation of the experimental parameters involved in the determination procedure. In total, 28 water samples with various matrix compositions and hardness contents were analyzed with satisfactory accuracy as evidenced by comparison of the results with EDTA complexometric titration. The method is free from interferences from environmentally significant metal cations and inorganic anions affording detection limits as low as 13.5 mg L(-1) CaCO(3) with the aid of a correction factor, which is determined by the non-linear absorbance properties of the solution mixture, and satisfactory reproducibility (RSD=4.21-8.08%).
在这项工作中，提出了一种基于多层层状囊泡和紧密双层的共凝聚相形成的快速水硬度分析方法，这些囊泡和双层是在碱性金属与羧酸阴离子表面活性剂在共表面活性剂（甲醇）存在下反应形成的。该方法利用了共凝聚相的光散射能力，通过在 350nm 处分光光度检测，可以将其与总硬度以碳酸钙当量为基础进行对数关联。该方法缩写为 HALC，源自碱性金属共凝聚的硬度测定，方法简单直接，可应用于各种基质组成和硬度含量的 28 种水样分析，具有令人满意的准确度，通过与 EDTA 络合滴定法的结果比较得到证实。该方法不受环境意义重大的金属阳离子和无机阴离子的干扰，通过校正因子可获得低至 13.5mgL(-1) CaCO(3)的检测限，校正因子由溶液混合物的非线性吸光度特性决定，且具有令人满意的重现性（RSD=4.21-8.08%）。
