Department of Environmental Geosciences, Centre for Microbiology and Environmental Systems Science, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria; Ghent University, Department of Chemistry, Atomic & Mass Spectrometry - A&MS Research Group, Campus Sterre, Krijgslaan 281-S12, 9000, Ghent, Belgium.
Department of Environmental Geosciences, Centre for Microbiology and Environmental Systems Science, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria; UFZ - Helmholtz Centre for Environmental Research, Department of Analytical Chemistry, Permoserstrasse 15, 04318, Leipzig, Germany.
Talanta. 2020 Aug 1;215:120921. doi: 10.1016/j.talanta.2020.120921. Epub 2020 Mar 15.
The implementation and enforcement of product labeling obligation as required, for example, by the cosmetic product regulation, needs simple and precise validated analytical methods. This also applies to the analysis of nanoparticles in products such as cosmetics. However, the provision of such methods is often hampered by inaccurate sizing due to unwanted nanoparticle changes, interference of matrix components with sizing and interactions between nanoparticles and analytical instrumentation. It is, therefore, necessary to develop appropriate sample preparation methods that preserve NP properties and reduce or remove matrix compounds that interfere with sizing. Further, accurate particle size analysis of samples containing unknown and possibly multiple nanoparticulate constituents is needed. In this study, we evaluated three sample preparation methods to identify and quantify TiO nanoparticles in sunscreens. Specifically, we used a combination of ultracentrifugation and hexane washing, thermal destruction of the matrix, and surfactant assisted particle extraction. The method accuracy was assessed by two internal reference samples: pristine TiO nanoparticles (NM104) and similar TiO nanoparticles dispersed in a sunscreen matrix. The PSDs were determined using an asymmetrical flow field-flow fractionation hyphenated with multi-angle light scattering and inductively coupled plasma-mass spectroscopy. Particle sizing was based on size calibration of the particle retention time in the AF. Computation of radius of gyration from MALS data was used as an orthogonal particle sizing approach to verify ideal elution and particle size data from the AF calibration. Among the three tested sample preparation methods surfactant assisted particle extraction revealed TiO nanoparticle recoveries of above 90% and no increase in particle size due to sample preparation was observed. Finally, the sample preparation methods were applied to two commercial sunscreen samples revealing the existence of TiO-NP < 100 nm. Conclusively, the surfactant assisted particle extraction method can provide valid data for TiO-NPs in sunscreen and possibly for cosmetic samples of similar matrix.
为了执行和实施产品标签义务，例如化妆品法规所要求的那样，需要简单而精确的经过验证的分析方法。这也适用于对化妆品等产品中的纳米颗粒进行分析。然而，由于纳米颗粒的尺寸不准确，由于不需要的纳米颗粒变化、基质成分对尺寸的干扰以及纳米颗粒与分析仪器之间的相互作用，这些方法的提供经常受到阻碍。因此，有必要开发适当的样品制备方法，以保留 NP 特性并减少或去除干扰尺寸的基质化合物。此外，还需要对含有未知和可能的多种纳米颗粒成分的样品进行准确的粒度分析。在这项研究中，我们评估了三种样品制备方法，以鉴定和定量防晒霜中的 TiO 纳米颗粒。具体来说，我们使用了超离心和正己烷洗涤、基质热破坏以及表面活性剂辅助颗粒提取的组合。通过两种内部参考样品评估方法的准确性：原始 TiO 纳米颗粒（NM104）和类似 TiO 纳米颗粒分散在防晒霜基质中。使用不对称流场流分离与多角度光散射和电感耦合等离子体质谱联用的方法测定 PSD。基于在 AF 中的颗粒保留时间进行尺寸校准来确定颗粒尺寸。使用 MALS 数据计算转动半径作为正交颗粒尺寸方法，以验证来自 AF 校准的理想洗脱和颗粒尺寸数据。在测试的三种样品制备方法中，表面活性剂辅助颗粒提取显示 TiO 纳米颗粒的回收率超过 90%，并且由于样品制备而没有观察到颗粒尺寸的增加。最后，将样品制备方法应用于两种商业防晒霜样品，结果表明存在 TiO-NP<100nm。总之，表面活性剂辅助颗粒提取方法可以为防晒霜中的 TiO-NP 以及类似基质的化妆品样品提供有效数据。
