基于饱和中链脂肪酸的凝固-漂浮分散液液微萃取/高效液相色谱法测定水样中紫外屏蔽剂

Determination of Ultraviolet Filters in Water Samples by High Performance Liquid Chromatography with Saturated Medium Chain Fatty Acid Based on Solidification-floating Dispersive Liquid-Liquid Microextraction

该文采用基于饱和中链脂肪酸的凝固-漂浮分散液液微萃取(SFO-DLLME)/高效液相色谱技术,建立了环境水样中4种紫外屏蔽剂的分析方法。以凝固点较高且密度小于水的饱和中链脂肪酸—辛酸为萃取剂,通过调节溶液pH值改变辛酸的存在形态,高pH值时辛酸以阴离子形式分散于溶液中完成萃取,低pH值时依靠其中性分子的强疏水作用实现油水分离,从而完成对环境水样中4种分析物的萃取。经单因素实验条件优化和响应曲面分析法计算,确定最佳萃取条件:萃取剂体积为100μL,氨水体积为100μL,浓硫酸体积为1.2 mL。在优化条件下,4种紫外屏蔽剂的线性范围为0.01~10.0 mg/L,检出限为0.18~0.76μg/L,富集倍数为42~49。在3个加标浓度下的回收率为73.8%~103%,日内及日间相对标准偏差为1.9%~9.6%。该方法具有简便、快速、环境友好等特点,进一步拓宽了分散液液微萃取技术的应用范围。

An high performance liquid chromatography with solidification-floating dispersive liquid-liquid microextraction(SFO-DLLME)based on saturated medium chain fatty acid was developed for the determination of four ultraviolet filters in environmental water samples.Octanoic acid,saturated medium chain fatty acid with a high melting point and a density less than water was used as the extractant,of which the existence form was changed by adjusting the pH of solution.An anionic extractant was dispersed in the solution for extraction at high pH,while a neutral extractant with high hydrophobicity emerged for separation from water at low pH.After optimization of the single factor condition and calculation of response surface method,the optimal conditions were as follows:the volume of extractant,ammonia and concentrated sulfuric acid were 100μL,100μL and 1.2 mL,respectively.The linearity range for the four ultraviolet filters were between 0.01 mg/L and 10.0 mg/L,with their detection limits of 0.18-0.76μg/L and enrichment factors of 42-49.The recoveries for the samples at three spiked levels ranged from 73.8%to 103%,with the intra-day and inter-day relative standard deviations(RSD)of 1.9%-9.6%.The proposed method was simple,rapid and environmentally friendly,which further broadened the application ranges and provided a new idea for the development of dispersive liquid-liquid microextraction.