University of Hohenheim, Institute of Food Chemistry, Garbenstrasse 28, 70599 Stuttgart, Germany.
J Chromatogr A. 2011 May 13;1218(19):2745-53. doi: 10.1016/j.chroma.2010.11.063. Epub 2010 Dec 3.
Sucralose, a persistent chlorinated substance used as sweetener, can already be found in waste water, and various countries focused on the release of sucralose into the aquatic environment. A quantitative high-performance thin-layer chromatography (HPTLC) method, which is orthogonal to existing methods, was developed to analyze sucralose in water. After sample preparation, separation of up to 17 samples was performed in parallel on a HPTLC plate silica gel 60 F(254) with a mixture of isopropyl acetate, methanol and water (15:3:1, v/v/v) within 15 min. Due to the weak native UV absorption of sucralose (≤200 nm), various post-chromatographic derivatization reactions were compared to selectively detect sucralose in effluent and surface water matrices. Thereby p-aminobenzoic acid reagent was discovered as a new derivatization reagent for sucralose. Compared to the latter and to β-naphthol, derivatization with aniline diphenylamine o-phosphoric acid reagent was slightly preferred and densitometry was performed by absorbance measurement at 400 nm. The limit of quantification (LOQ) of sucralose in drinking and surface water was calculated to be 100 ng/L for a given recovery rate of 80% and the extraction of a 0.5 L water sample. The sucralose content determined in four water samples obtained during an interlaboratory trial in 2008 was in good agreement to the mean laboratory values of that trial. According to the t-test, which compares the results with the target value, the means obtained by HPTLC were not significantly different from the respective means of six laboratories, analyzed by HPLC-MS/MS or HPLC-TOF-MS with the use of mostly isotopically labeled standards. The good accuracy and high sample throughput capacity proved HPTLC as a well suited method regarding quantification of sucralose in various aqueous matrices.
三氯蔗糖是一种作为甜味剂使用的持久性氯化物质，已经在废水中被发现，各国都关注三氯蔗糖在水环境中的释放情况。本文开发了一种与现有方法正交的定量高效薄层色谱（HPTLC）方法，用于分析水中的三氯蔗糖。在样品制备后，在 HPTLC 板硅胶 60 F（254）上可同时分离多达 17 个样品，分离时间为 15 分钟，采用异丙基乙酸酯、甲醇和水（15:3:1，v/v/v）的混合物。由于三氯蔗糖的天然紫外吸收较弱（≤200nm），比较了各种衍生化反应以选择性检测废水和地表水基质中的三氯蔗糖。结果发现对氨基苯甲酸试剂是三氯蔗糖的一种新的衍生化试剂。与后两者相比，苯胺二苯胺邻磷酸试剂的衍生化略有优势，并通过在 400nm 处进行吸光度测量进行密度测量。在回收率为 80%的情况下，饮用水和地表水中三氯蔗糖的定量下限（LOQ）计算为 100ng/L，提取 0.5L 水样。2008 年进行的实验室间试验中获得的四个水样中的三氯蔗糖含量与该试验的实验室平均值吻合良好。根据 t 检验（将结果与目标值进行比较），HPTLC 获得的平均值与使用大多同位素标记标准品通过 HPLC-MS/MS 或 HPLC-TOF-MS 分析的六个实验室的平均值无显著差异。良好的准确性和高样品通量能力证明 HPTLC 是一种适合于各种水基质中三氯蔗糖定量分析的方法。
