diplomsko delo
Maja Mahnič (Author), Anton Meden (Mentor)

Abstract

Rentgenska praškovna difrakcija je metoda, s katero lahko analiziramo kristalinične snovi in poskušamo identificirati prisotne kristalne faze v neznanih vzorcih. Metoda temelji na uklanjanju rentgenskih žarkov na elektronih, kjer do uklona pride le, če so izpolnjeni vsi pogoji Braggovega zakona. Ko kristaliničen vzorec posnamemo na difraktometru, dobimo zanj značilen praškovni posnetek oziroma difraktogram, katerega v nadaljevanju analiziramo s pomočjo računalniških programov. Da sem spoznala prednosti in omejitve metode, sem si za analizo izbrala dvanajst različnih zdravil proti povišanemu krvnemu tlaku. Vzorce sem ustrezno pripravila, jih poslala na snemanje in s pomočjo dobljenih difraktogramov izvedla kvalitativno fazno analizo vzorcev. Analizo so mi omogočili trije različni računalniški programi. Najprej sem s programom X'Pert HighScore Plus odprla posnete difraktograme in jih primerjala med seboj, nato pa sem s programom Crystallographica Search-Match izvedla identifikacijo prisotnih faz v vzorcih. Pri nekaterih vzorcih sem si morala pomagati še z zbirko podatkov PDF-5+, kjer sem pridobila podrobnejše informacije o iskani snovi, katere sem nato vnesla v program CSM. Na podlagi podobnosti difraktogramov in vsebnosti enakih faz, sem vzorce razdelila v pet skupin. Na koncu sem svoje rezultate primerjala z deklaracijami zdravil in ugotovila, da sem pri skoraj vseh vzorcih uspela identificirati glavne učinkovine zdravil. Neidentificirane so ostale pomožne snovi in tudi nekatere glavne učinkovine, ki so v vzorcih prisotne v premajhnem odstotku ali pa imajo amorfno zgradbo, zato jih z metodo rentgenske praškovne difrakcije ni mogoče določiti.

Keywords

zdravila proti povišanemu krvnemu tlaku;rentgenska praškovna difrakcija;identifikacija kristalnih faz;diplomska dela;

Data

Language: Slovenian
Year of publishing:
Typology: 2.11 - Undergraduate Thesis
Organization: UL FKKT - Faculty of Chemistry and Chemical Technology
Publisher: [M. Mahnič]
UDC: 543.442.3(043.2)
COBISS: 207278083 Link will open in a new window
Views: 46
Downloads: 30
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Other data

Secondary language: English
Secondary title: X-ray powder diffraction analysis of antihypertensive medicines
Secondary abstract: X-ray powder diffraction is a method used for analysing crystalline materials and identifying phases in unknown samples. The method is based on the diffraction of X-rays on electrons, where diffraction occurs only if all the conditions of Bragg’s law are fulfilled. When a crystalline sample is recorded on a diffractometer, a characteristic powder image or diffractogram is obtained, which is then analysed using different computer programmes. To understand advantages and limitations of the method, I chose to analyse twelve different antihypertensive medicines. I prepared the samples, sent them for recording and performed a qualitative phase analysis using the recorded diffractograms. The analysis was enabled by using three different computer programmes. Firstly, I used X’Pert HighScore Plus to open the recorded diffractograms and compare them with each other, and then I used Crystallographica Search-Match to identify the phases in the samples. For some samples, I had to use program PDF+ to obtain more information about some substances, which I then entered into the CSM program. Based on the similarity of the diffractograms and the content of the same phases, I divided the samples into five groups. Finally, I compared my results with the declarations of the medicines and found out that I was able to identify the main active substances in almost all samples. The remaining excipients and some main active substances that were not identified were those that were present in the samples in too low percentage or had amorphous structure that could not be determined by X-ray powder diffraction.
Secondary keywords: antihypertensive drugs;X-ray powder diffraction;crystal phase identification;Kristalna struktura;Kvalitativna analiza (kemija);Antihipertenzivi;Univerzitetna in visokošolska dela;
Type (COBISS): Bachelor thesis/paper
Study programme: 1000373
Embargo end date (OpenAIRE): 1970-01-01
Thesis comment: Univ. v Ljubljani, Fak. za kemijo in kemijsko tehnologijo, UNI Kemija
Pages: 1 spletni vir (1 datoteka PDF (47 str.))
ID: 24956296