The use of makeup powders dates back to the days of the ancient Egyptians, almost 6000 years ago, where such powders were used only by the upper classes. Today, cosmetics are accessible to everyone and at every turn, so many times this part of the industry is uncontrolled, especially on the World Wide Web. Therefor I decided to check their phase composition and compare it to the declaration on the products. I was also interested in the presence of any other substance that is not listed on the declaration. Crystalline substances in loose powders were identified by X-ray powder diffraction.
X-ray powder diffraction is a technique for characterizing crystalline substances. We use X-ray radiation of a certain wavelength to irradiate the sample. This results in deflections recorded by the detector. The result is diffractogram with which we can identify substances. In my diploma work, I analyzed 14 compact powders. I processed the diffractograms using the X'Pert HighScore Plus program, in which I compared the samples with each other and classified them into groups based on common peaks. The next step followed in Crystallographica Search-Match, where I compared the standards in the PDF database with the sample diffractograms.
By analysis, I found that talc and the mineral muscovite predominated, as declared on the products. The declarations also listed a variety of organic substances such as stearates, fats, oils and many other substances that I did not detect in the analysis because they may be amorphous or present in small quantities, thus below the detection limit.