Alshana Usama, Ertaş Nusret, Göğer Nilgün G
Department of Analytical Chemistry, Faculty of Pharmacy, Gazi University, 06330 Ankara, Turkey; Department of Food Engineering, Faculty of Engineering and Architecture, Avrasya University, 61250 Trabzon, Turkey.
Department of Analytical Chemistry, Faculty of Pharmacy, Gazi University, 06330 Ankara, Turkey.
Food Chem. 2015 Aug 15;181:1-8. doi: 10.1016/j.foodchem.2015.02.074. Epub 2015 Feb 20.
Dispersive liquid-liquid microextraction (DLLME) with back-extraction was used prior to capillary electrophoresis (CE) for the extraction of four parabens. Optimum extraction conditions were: 200 μL chloroform (extraction solvent), 1.0 mL acetonitrile (disperser solvent) and 1 min extraction time. Back-extraction of parabens from chloroform into a 50mM sodium hydroxide solution within 10s facilitated their direct injection into CE. The analytes were separated at 12°C and 25 kV with a background electrolyte of 25 mM borate buffer containing 5.0% (v/v) acetonitrile. Enrichment factors were in the range of 4.3-10.7 and limits of detection ranged from 0.1 to 0.2 μg mL(-1). Calibration graphs showed good linearity with coefficients of determination (R(2)) higher than 0.9957 and relative standard deviations (%RSDs) lower than 3.5%. DLLME-CE was demonstrated to be a simple and rapid method for the determination of parabens in human milk and food with relative recoveries in the range of 86.7-103.3%.
在进行毛细管电泳（CE）分析之前，采用带反萃取的分散液液微萃取（DLLME）法萃取四种对羟基苯甲酸酯。最佳萃取条件为：200 μL氯仿（萃取溶剂）、1.0 mL乙腈（分散剂溶剂）以及1分钟萃取时间。在10秒内将对羟基苯甲酸酯从氯仿反萃取至50 mM氢氧化钠溶液中，便于其直接进样到CE中。分析物在12°C和25 kV的条件下进行分离，背景电解质为含5.0%（v/v）乙腈的25 mM硼酸盐缓冲液。富集因子在4.3 - 10.7范围内，检测限在0.1至0.2 μg mL⁻¹之间。校准曲线显示出良好的线性，决定系数（R²）高于0.9957，相对标准偏差（%RSDs）低于3.5%。结果表明，DLLME - CE是一种用于测定人乳和食品中对羟基苯甲酸酯的简单快速方法，相对回收率在86.7 - 103.3%范围内。
