Waluvanaruk Jitwilai, Aeungmaitrepirom Wanlapa, Tuntulani Thawatchai, Ngamukot Passapol
Department of Chemistry, Faculty of Science, Chulalongkorn University.
Anal Sci. 2014;30(3):389-95. doi: 10.2116/analsci.30.389.
The silica gel modified with benzothiazole calix[4]arene (APS-L1) via Schiff's base reaction was applied as a sorbent in an online system for preconcentration and determination of silver ion by flame atomic absorption spectrometry (FAAS). APS-L1 was used as an effective sorbent for solid phase extraction (SPE) of silver(I) ion in both batch and column methods. The optimum experimental parameters such as pH, eluent type, sample flow rate, eluent volume and eluent flow rate including the effect of interfering ions were investigated. Silver(I) ion was determined at pH 6-7. The capacity of APS-L1 sorbent was found to be 12.2 mg/g of sorbent. The high affinity was obtained without interference from the interfering ions. The optimum conditions of the online flow injection preconcentration coupled with the FAAS (FI-FAAS system) were evaluated. The sample flow rate was 3.0 mL min(-1) using sample volume of 5-10 mL. Elution was performed with 250 μL of 0.1 mol L(-1) thiosulfate at the flow rate of 1.5 mL min(-1). The analytical characteristics and performance of the FI-FAAS system were studied under optimum conditions using a solution spiked with standard silver(I) ion at 20 and 50 μg L(-1). The detection limit of 0.44 μg L(-1) was obtained. The accuracy of the proposed method was evaluated and percentages of recovery at 20 and 50 μg L(-1) were 100.2 and 99.5%, respectively. The percent relative standard deviations (%RSD) at 20 and 50 μg L(-1) were 6.1 and 3.3%, respectively. The developed method was successfully applied to determine trace silver(I) ion in drinking and tap water samples.
通过席夫碱反应制备的苯并噻唑杯[4]芳烃修饰硅胶（APS-L1）被用作在线系统中的吸附剂，用于火焰原子吸收光谱法（FAAS）预富集和测定银离子。APS-L1在分批和柱法中均用作固相萃取（SPE）银（I）离子的有效吸附剂。研究了最佳实验参数，如pH值、洗脱剂类型、样品流速、洗脱剂体积和洗脱剂流速，以及干扰离子的影响。在pH 6-7条件下测定银（I）离子。发现APS-L1吸附剂的容量为12.2 mg/g吸附剂。在不受干扰离子干扰的情况下获得了高亲和力。评估了在线流动注射预富集与FAAS联用（FI-FAAS系统）的最佳条件。使用5-10 mL的样品体积，样品流速为3.0 mL min⁻¹。用250 μL 0.1 mol L⁻¹硫代硫酸盐以1.5 mL min⁻¹的流速进行洗脱。在最佳条件下，使用添加了20和50 μg L⁻¹标准银（I）离子的溶液研究了FI-FAAS系统的分析特性和性能。获得了0.44 μg L⁻¹的检测限。评估了所提方法的准确性，在20和50 μg L⁻¹时的回收率分别为100.2%和99.5%。在20和50 μg L⁻¹时的相对标准偏差百分比（%RSD）分别为6.1%和3.3%。所建立的方法成功应用于饮用水和自来水样品中痕量银（I）离子的测定。
