Kvalitativna fazna analiza zobnih past z rentgensko praškovno difrakcijo

Bele, Leja (author), Meden, Anton (mentor)

Zobna pasta je poltrdna snov, ki jo uporabljamo za čiščenje zob večkrat na dan. Glede na pogostost uporabe sem se vprašala o njeni sestavi. Zanimalo me je predvsem, katere anorganske abrazive vsebujejo tovrstni kozmetični izdelki. Glavni cilj je bil spoznati rentgensko praškovno difrakcijo tako teoretično kot tudi praktično. Rentgenska praškovna difrakcija je ena izmed glavnih metod za karakterizacijo trdnih snovi. Pri njej obsevamo vzorce z rentgensko svetlobo specifične valovne dolžine in iz uklonske slike določimo različne karakteristike materiala. Zbrala sem 18 vzorcev različnih zobnih past in jih poslala na kemijski inštitut, kjer so bili posneti difraktogrami. Nato je sledila analiza dobljenih difraktogramov s pomočjo računalniških programov X`pert HighScore Plus in Crystallographica Search-Match. Ker z anorganskimi standardi nisem pojasnila vseh vrhov, sem poskusila tudi s programom, ki izračuna difraktograme iz struktur organskih spojin. Pri tem sem uporabila dva programa in sicer ConQuest in Mercury. Ugotovila sem, da večina izbranih vzorcev zobnih past vsebuje anorganski abraziv TiO2 v obliki anatasa. Identificirala pa sem tudi druge, kot so natrijev bikarbonat, hidroksiapatit, kalijev fosfat itd. Natrijev bikarbonat spada po trdoti med milejše abrazive, našla sem ga v eni zobni pasti. Ta je namenjena predvsem za tiste, ki imajo težave s krvavečimi dlesnimi, zato sem tudi pričakovala abraziv z nižjo trdoto. Za analizo sem izbrala 3 otroške zobne paste. Pričakovala sem vsebnost milejših abrazivov, kot so natrijev bikarbonat ali kalcijev karbonat. Prevec abrazivna zobna pasta lahko sčasoma obrabi otrokovo zobno sklenino. Ugotovila sem, da dve vsebujeta anorganski abraziv TiO2, ki spada med srednje trde abrazive.

• Language: Slovenian
• Keywords: zobna pasta, rentgenska praškovna difrakcija, anorganski abrazivi, difraktogram
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Year: 2023
• PID: 20.500.12556/RUL-149228
• COBISS.SI-ID: 167311875
• Publication date in RUL: 05.09.2023

Secondary language

• Language: English
• Title: Qualitative phase analysis of toothpaste by X-ray powder diffraction

Abstract

Toothpaste is a semi-solid substance that we use several times a day to clean our teeth. Given the frequency of use, I wondered about its composition. In particular, I was interested in which inorganic abrasives are contained in such cosmetic products. The main objective was to learn about X-ray powder diffraction both theoretically and practically. X-ray powder diffraction is one of the main methods for characterising solid substances. It involves irradiating samples with X-ray light of a specific wavelength and determine various characeristics of a material from its diffraction pattern. I collected 18 samples of different toothpastes and sent them to the Institute of Chemistry, where diffractograms were collected. The resulting diffractograms were then analysed using computer software X`pert HighScore Plus and Crystallographica Search-Match. Since I couldn't explain all the peaks with the inorganic standards, I also tried using a program that calculates the diffractograms for the structures of organic compounds. I found that most of the selected toothpaste samples contained the inorganic abrasive TiO2 in the form of anatase. I also found others like sodium bicarbonate, hydroxyapatite, potassium phosphate, etc. Sodium bicarbonate is one of the milder abrasives in terms of hardness, and I found it in one toothpaste. This one is mainly for bleeding gums, so I was expecting a lower hardness abrasive. I have selected 3 children's toothpastes for analysis. I expected to find milder abrasives such as sodium bicarbonate or calcium carbonate. Toothpaste that is too abrasive can wear away child's tooth enamel over time. I found that two of them contain the inorganic abrasive TiO2, which is a medium-hard abrasive.

• Keywords: toothpaste, X-ray powder diffraction, inorganic abrasives, diffractogram