Analiza pudrov v prahu z rentgensko praškovno difrakcijo

KRIŽAN, METKA (author), Meden, Anton (mentor)

Uporaba pudrov v prahu sega v čase starih Egipčanov, skoraj 6000 let nazaj, kjer so pudre uporabljali le višji sloji. Danes je kozmetika dostopna vsem in na vsakem koraku, zato je mnogokrat ta del industrije nenadzorovan, zlasti na svetovnem spletu. Zato sem se odločila, da bom preverila njihovo fazno sestavo in jo primerjala z deklaracijo na izdelkih. Zanimalo me je tudi, če je prisotna še kakšna druga snov, ki ni zavedena na deklaraciji. Kristalinične snovi v pudrih v prahu sem identificirala s pomočjo rentgenske praškovne difrakcije. Rentgenska praškovna difrakcija je tehnika za karakterizacijo kristaliničnih snovi. Pri tem uporabljamo rentgensko svetlobo določene valovne dolžine, s katero obsevamo vzorec. Pri tem pride do uklonov, ki jih beleži detektor. Rezultat so difraktogrami, s katerimi lahko identificiramo snovi. V diplomskem delu sem analizirala 14 pudrov v prahu. Difraktograme sem obdelala s pomočjo programa X'Pert HighScore Plus, v katerem sem vzorce primerjala med seboj in na podlagi skupnih vrhov razvrstila v skupine. Naslednji korak je sledil v programu Crystallographica Search-Match, kjer sem primerjala standarde v podatkovni zbirki PDF z difraktogrami vzorcev. Z analizo sem ugotovila, da sta prevladovala predvsem smukec in mineral muskovit, kot je bilo deklarirano na izdelkih. Na deklaraciji so bile zapisane še najrazličnejše organske snovi, kot so stearati, masti, olja in mnoge druge snovi, ki jih v analizi nisem zaznala, ker so morda amorfne ali pa so prisotne v majhni količini, da so pod mejo detekcije.

• Language: Slovenian
• Keywords: rentgenska praškovna difrakcija, difraktogram, kvalitativna fazna analiza, pudri v prahu.
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Year: 2020
• PID: 20.500.12556/RUL-124094
• COBISS.SI-ID: 46034947
• Publication date in RUL: 29.12.2020

Secondary language

• Language: English
• Title: Analysis of makeup powders using X-ray powder diffraction

Abstract

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.

• Keywords: X-ray powder diffraction, diffractogram, qualitative phase analysis, makeup compact powders.