State Key Laboratory Breeding Base of Eco-Environments and Bio-Resources of the Three Gorges Reservoir Region, College of Chemistry and Chemical Engineering, Southwest University , Chongqing 400715, People's Republic of China.
J Agric Food Chem. 2014 Jun 25;62(25):5818-26. doi: 10.1021/jf5006403. Epub 2014 Jun 11.
Dispersive liquid-phase microextraction with solidification of floating organic drop (SFO-DLPME) is one of the most interesting sample preparation techniques developed in recent years. In this paper, a new, rapid, and efficient SFO-DLPME coupled with high-performance liquid chromatography (HPLC) was established for the extraction and sensitive detection of banned Sudan dyes, namely, Sudan I, Sudan II, Sudan III, and Sudan IV, in foodstuff and water samples. Various factors, such as the type and volume of extractants and dispersants, pH and volume of sample solution, extraction time and temperature, ion strength, and humic acid concentration, were investigated and optimized to achieve optimal extraction of Sudan dyes in one single step. After optimization of extraction conditions using 1-dodecanol as an extractant and ethanol as a dispersant, the developed procedure was applied for extraction of the target Sudan dyes from 2 g of food samples and 10 mL of the spiked water samples. Under the optimized conditions, all Sudan dyes could be easily extracted by the proposed SFO-DLPME method. Limits of detection of the four Sudan dyes obtained were 0.10-0.20 ng g(-1) and 0.03 μg L(-1) when 2 g of foodstuff samples and 10 mL of water samples were adopted, respectively. The inter- and intraday reproducibilities were below 4.8% for analysis of Sudan dyes in foodstuffs. The method was satisfactorily used for the detection of Sudan dyes, and the recoveries of the target for the spiked foodstuff and water samples ranged from 92.6 to 106.6% and from 91.1 to 108.6%, respectively. These results indicated that the proposed method is simple, rapid, sensitive, and suitable for the pre-concentration and detection of the target dyes in foodstuff samples.
分散液液微萃取-漂浮有机溶剂萃取（SFO-DLPME）是近年来发展起来的最有趣的样品制备技术之一。在本文中，建立了一种新的、快速的、高效的 SFO-DLPME 与高效液相色谱（HPLC）相结合的方法，用于食品和水样中禁用苏丹染料（苏丹 I、苏丹 II、苏丹 III 和苏丹 IV）的提取和灵敏检测。考察并优化了各种因素，如萃取剂和分散剂的类型和体积、样品溶液的 pH 值和体积、萃取时间和温度、离子强度和腐殖酸浓度，以实现苏丹染料在一步中的最佳萃取。在用 1-十二醇作为萃取剂和乙醇作为分散剂优化萃取条件后，该方法被应用于从 2 g 食品样品和 10 mL 加标水样中提取目标苏丹染料。在优化条件下，通过所提出的 SFO-DLPME 方法可以轻松提取所有苏丹染料。当采用 2 g 食品样品和 10 mL 水样时，四种苏丹染料的检测限分别为 0.10-0.20ng g(-1)和 0.03μg L(-1)。在食品中分析苏丹染料时，日内和日间重现性低于 4.8%。该方法可用于检测苏丹染料，添加的食品和水样的目标回收率范围分别为 92.6%至 106.6%和 91.1%至 108.6%。这些结果表明，该方法简单、快速、灵敏，适用于食品样品中目标染料的预浓缩和检测。
