Department of Chemistry, Faculty of Sciences, Azarbaijan University of Tarbiat Moallem, 35 Km Tabriz-Marageh Road, P.O. Box 53714-161, Tabriz, Iran.
Talanta. 2011 Apr 15;84(2):368-73. doi: 10.1016/j.talanta.2011.01.026. Epub 2011 Jan 19.
The nickel-aluminum layered double hydroxide (Ni-Al LDH) was synthesized by a simple co-precipitation method and used as a solid-phase extraction (SPE) sorbent for separation and pre-concentration of trace levels of salicylic acid (SA) from aqueous solutions. Extraction of analyte is based on the adsorption of salicylate ions on the Ni-Al (NO(3)(-)) LDH and/or their exchanging with LDH interlayer NO(3)(-) ions. The retained analyte on the LDH was stripped by 3 mol L(-1) NaOH solution and its concentration was subsequently determined spectrofluorometrically at λ(em)=400 nm with excitation at λ(ex)=270 nm. Various parameters affecting the extraction efficiency of SA on the Ni-Al (NO(3)(-)) LDH, such as pH, amount of nano-sorbent, sample loading flow rate, elution conditions, sample volume and matrix effects were investigated. In the optimum experimental conditions, the limit of detection (3s) and enrichment factor were 0.12 μg L(-1) and 40, respectively. The relative standard deviation (RSD) for six replicate determinations of 10 μg L(-1) SA was 2.3%. The calibration graph using the pre-concentration system was linear in the range of 0.3-45 μg L(-1) with a correlation coefficient of 0.9985. The optimized method was successfully applied to the determination of SA in blood serum, willow leaf and aspirin tablet.
镍-铝层状双氢氧化物（Ni-Al LDH）通过简单的共沉淀法合成，并用作固相萃取（SPE）吸附剂，用于从水溶液中分离和预浓缩痕量水杨酸（SA）。分析物的提取基于水杨酸盐离子在 Ni-Al（NO3-）LDH 上的吸附和/或它们与 LDH 层间 NO3-离子的交换。保留在 LDH 上的分析物用 3 mol L-1 NaOH 溶液洗脱，并用 270nm 激发时在 400nm 处进行荧光光谱法测定。研究了各种影响 Ni-Al（NO3-）LDH 上 SA 萃取效率的参数，如 pH 值、纳米吸附剂用量、样品加载流速、洗脱条件、样品体积和基质效应。在最佳实验条件下，检测限（3s）和富集因子分别为 0.12μg L-1和 40。在 10μg L-1 SA 的 6 次重复测定中，相对标准偏差（RSD）为 2.3%。使用预浓缩系统的校准曲线在线性范围内为 0.3-45μg L-1，相关系数为 0.9985。优化后的方法成功应用于血清、柳叶和阿司匹林片剂中 SA 的测定。
