People are becoming more and more aware of the importance of our health and more and more people are taking effervescent tablets for prevention, mostly as a dietary supplement, but also as a painkiller or to relieve coughs. Effervescent tablets usually consist of solid, crystalline substances. Such substances have a long-range order or periodicity. This means that the matter consists of a mass of crystals, the basic unit of which is the unit cell, which is repeated in all directions in an orderly manner, forming a highly ordered structure.
One of the basic methods for identifying solid crystalline substances is X-ray powder diffraction. This is a method in which the sample is illuminated with X-rays. When the beams reach the sample, interference occurs at different diffraction angles due to the presence of crystalline phases in the sample. For this to occur, the Bragg condition must be satisfied. The result of the analysis is a diffraction image, a so-called powder snapshot or diffractogram. It shows the dependence of the intensity of the diffracted rays on the diffraction angle and can be used to identify crystalline phases.
I analyzed 17 samples of effervescent tablets by X-ray powder diffraction. The samples were recorded with a diffractometer and the diffractograms were compared with each other and with their declaration. For this purpose, I used different computer programs (X’Pert High-score and Crystallographica Search-Match). In this way, I also learned about the limitations of the method. I found that, using this method, I could only identify the main components of the effervescent tablets. Unidentified compounds from the effervescent tablet declaration remain and are present in the tablets in small amounts.
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