Measurement of Titanium Dioxide in Cosmetic Products with X-Ray Fluorescence Spectrometry

Abstract

This paper reports the development of a simple method for measuring titanium dioxide in cosmetic products using X-ray fluorescence. A sample is prepared by stirring in a dispersion medium and then filtering with a 0.1 μm pore size membrane filter. The titanium dioxide particles trapped on the dried membrane filter are then measured with a wave-length dispersive X-ray fluorescence spectrometer. This sample preparation procedure was investigated using scanning electron microscopy (SEM), energy dispersive X-ray fluorescence (EDX) mapping, inductively coupled plasma atomic emission spectrometry (ICP-AES) and turbidimetry. Interferences can be separated from the titanium dioxide layer on the membrane filter with this preparation procedure. The relative standard deviation for the analysis is less than 0.4%, the recovery is more than 99.0%, and the calibration curve gives a correlation coefficient of R = 1.000. The detection limit for titanium dioxide using this procedure is 0.02% by weight in product. This method is applicable to various cosmetic products containing powdered titanium dioxide.