Vidal Lorena, Chisvert Alberto, Canals Antonio, Salvador Amparo
Departamento de Química Analítica, Nutrición y Bromatología, Facultad de Ciencias, Universidad de Alicante, P.O. Box 99, E-03080 Alicante, Spain.
J Chromatogr A. 2007 Dec 7;1174(1-2):95-103. doi: 10.1016/j.chroma.2007.07.077. Epub 2007 Aug 6.
Benzophenone-3 (BZ3), one of the compounds most commonly used as UV filter in cosmetic products, can be absorbed through the skin into the human body, since it can be found at trace levels in urine from users of cosmetic products that contain BZ3. Moreover, different undesirable effects have been attributed to this compound. Thus, sensitive analytical methods to monitor urinary excretion of this compound should be developed. This paper presents a selective and sensitive methodology for BZ3 determination at ultratrace levels in human urine samples. The methodology is based on a novel microextraction technique, known as single-drop microextraction (SDME). An ionic liquid (IL) has been used as extractant phase instead of an organic solvent. After the microextraction process, the extractant phase was injected into a liquid chromatography system. The variables of interest in the SDME process were optimized using a multivariate optimization approach. A Plackett-Burman design for screening and a circumscribed central composite design for optimizing the significant variables were applied. Ionic strength, extraction time, stirring speed, pH, ionic liquid type, drop volume and sample volume were the variables studied. The optimum experimental conditions found were: sodium chloride concentration, 13% (w/v); extraction time, 25 min; stirring speed, 900 rpm; pH, 2; ionic liquid type, 1-hexyl-3-methylimidazolium hexafluorophosphate ([C(6)MIM][PF(6)]); drop volume, 5 microL; and sample volume, 10 mL. The proposed method requires a standard addition calibration approach, and it has been successfully employed to determine free BZ3 in urine samples coming from human volunteers who applied a sunscreen cosmetic containing this UV filter. The limit of detection was in the order of 1.3 ng mL(-1) and repeatability of the method, expressed as relative standard deviation, was 6% (n=8).
二苯甲酮 - 3（BZ3）是化妆品中最常用的紫外线过滤剂之一，它可以通过皮肤被人体吸收，因为在含有BZ3的化妆品使用者的尿液中可以检测到痕量水平的该物质。此外，这种化合物还具有不同的不良影响。因此，应开发灵敏的分析方法来监测该化合物的尿排泄情况。本文提出了一种用于测定人尿样中超痕量水平BZ3的选择性灵敏方法。该方法基于一种新型微萃取技术，即单滴微萃取（SDME）。使用离子液体（IL）作为萃取相代替有机溶剂。微萃取过程完成后，将萃取相注入液相色谱系统。采用多变量优化方法对SDME过程中的相关变量进行了优化。应用Plackett - Burman设计进行筛选，并应用外接中心复合设计对显著变量进行优化。研究的变量包括离子强度、萃取时间、搅拌速度、pH值、离子液体类型、液滴体积和样品体积。找到的最佳实验条件为：氯化钠浓度13%（w/v）；萃取时间25分钟；搅拌速度900转/分钟；pH值2；离子液体类型为1 - 己基 - 3 - 甲基咪唑六氟磷酸盐（[C(6)MIM][PF(6)]）；液滴体积5微升；样品体积10毫升。所提出的方法需要采用标准加入校准法，并且已成功用于测定来自涂抹含有这种紫外线过滤剂的防晒化妆品的人类志愿者尿样中的游离BZ3。检测限约为1.3纳克/毫升，该方法的重复性以相对标准偏差表示为6%（n = 8）。
