Department of Analytical Chemistry, Faculty of Sciences, University of Granada, Av. Fuentenueva s/n, 18071 Granada, Spain.
Anal Bioanal Chem. 2011 May;400(5):1329-38. doi: 10.1007/s00216-011-4682-3. Epub 2011 Jan 31.
Dispersive liquid-liquid microextraction (DLLME) has been proposed for the extraction and preconcentration of 12 carbamate pesticides in juice samples, followed by their determination by micellar electrokinetic chromatography with diode-array detection. To improve sensitivity, an on-capillary sample concentration method based on sweeping has been developed. Also, separations were performed in an extended light path fused-silica capillary; the separation buffer consisted of 100 mM borate and 50 mM SDS (pH 9.0) with 5% acetonitrile. Samples were introduced by hydrodynamic injection, dissolved in the separation buffer, but free of micelles. Several parameters of the DLLME procedure (such as type and volume of extraction and dispersive solvents, pH, salt addition, and extraction time) were optimized. Recoveries obtained for fortified juice samples (banana, pineapple, and tomato) at three different concentration levels, ranged from 78% to 105%, with relative standard deviations lower than 9%. The limits of detection ranged from 1 to 7 μg l(-1). Moreover, the method is fast, simple, and environmentally friendly.
分散液液微萃取（DLLME）已被提议用于果汁样品中 12 种氨基甲酸酯类农药的提取和预浓缩，然后通过胶束电动色谱与二极管阵列检测进行测定。为了提高灵敏度，开发了一种基于扫集的毛细管内样品浓缩方法。此外，分离在延长光程熔融石英毛细管中进行；分离缓冲液由 100mM 硼酸盐和 50mM SDS（pH9.0）组成，含有 5%乙腈。样品通过液压注射进样，溶解在分离缓冲液中，但不含胶束。优化了 DLLME 过程的几个参数（如萃取和分散溶剂的类型和体积、pH 值、盐的添加和萃取时间）。在三个不同浓度水平下，对加标果汁样品（香蕉、菠萝和番茄）的回收率为 78%至 105%，相对标准偏差低于 9%。检测限范围为 1 至 7μg l(-1)。此外，该方法快速、简单、环保。
