To determine the trace amount of four benzoic acid esters in cosmetics, ionic dispersive liquid–liquid microextraction (DLLME) and magnetic solid-phase extraction were combined and optimized. After solvent optimization, 1-octyl-3-methylimidazolium hexafluorophosphate was selected as the extraction solvent to form hydrophobic droplets in the process of ionic DLLME, followed by removal of ions from the sample solution containing Fe 3 O 4 @GO nano-materials. The magnetic nano-materials were characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, and vibrating sample magnetometer. Some parameters affecting the efficiency of extraction were optimized using Box-Behnken design. Under optimized conditions, the limit of detection for all the preservatives was less than 0.135 mg/L and the accuracy ranged from 88.5% to 101%. This technology could determine the trace amount of preservatives in cosmetics with comparatively higher accuracy and sensitivity.

中文翻译：

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磁性固相-离子分散液-液萃取-高效液相色谱法测定化妆品中的四种对羟基苯甲酸酯

为了测定化妆品中痕量的四种苯甲酸酯，将离子分散液-液微萃取（DLLME）和磁性固相萃取相结合并进行了优化。经过溶剂优化后，选择六氟磷酸1-辛基-3-甲基咪唑鎓作为萃取溶剂，在离子DLLME过程中形成疏水性液滴，然后从含有Fe 3 O 4 @GO纳米材料的样品溶液中去除离子。使用傅立叶变换红外光谱，扫描电子显微镜，透射电子显微镜和振动样品磁强计对磁性纳米材料进行了表征。使用Box-Behnken设计优化了一些影响提取效率的参数。在优化条件下，所有防腐剂的检出限均小于0。135 mg / L，准确度范围为88.5％至101％。这项技术可以以较高的准确性和灵敏度确定化妆品中的痕量防腐剂。