Departamento de Química Analítica y Alimentaria, Área de Química Analítica, Facultad de Química, Universidad de Vigo, Campus As Lagoas-Marcosende s/n, 36310 Vigo, Spain.
Anal Chim Acta. 2012 Mar 16;719:61-7. doi: 10.1016/j.aca.2011.12.061. Epub 2012 Jan 8.
A headspace single drop microextraction procedure is proposed for terpene screening in fragrance-free cosmetics. The drop is composed by an aqueous solution of a fluorescence probe formed by bovine serum albumin and fluorescein. Extracted volatile terpenes produce a fluorescence quenching that can be monitored by microvolume-fluorospectrometry. This quenching is observed on the fluorescein fluorescence only when it is linked to bovine serum albumin. A mechanism of contact quenching is proposed. Variables related to the terpene microextraction procedure were carefully studied, namely drop composition and volume, microextraction time, sample volume and temperature, stirring rate and salt addition. The only sample treatment is the dilution of cosmetic with 40% (v/v) ethanol. Citronellol was selected as a representative terpene for calibration purposes. According to the European legislation, the probability-concentration graph of the screening system was established using 0.001% (w/w) as the cut-off level. Low limits of detection with simple instrumentation, absence of matrix effects and high sample throughput can be emphasized.
提出了一种用于无香化妆品中萜烯筛选的顶空单滴微萃取程序。该液滴由牛血清白蛋白和荧光素形成的荧光探针的水溶液组成。提取的挥发性萜烯产生荧光猝灭，可以通过微量荧光光谱法监测。只有当荧光素与牛血清白蛋白结合时，才会观察到这种猝灭。提出了一种接触猝灭机制。仔细研究了与萜烯微萃取程序相关的变量，即液滴组成和体积、微萃取时间、样品体积和温度、搅拌速度和加盐。唯一的样品处理是用 40%（体积/体积）乙醇稀释化妆品。根据欧洲法规，使用 0.001%（重量/重量）作为截止水平，建立了筛选系统的概率-浓度图。可以强调简单仪器的低检测限、无基质效应和高样品通量。
