Delovne značilnosti modularnega molekularnega fluorescenčnega spektrometra

Hriberšek, Zala (avtor), Gros, Nataša (mentor)

V diplomskem delu sem ovrednotila obnašanje modularnega molekularnega fluorescenčnega spektrometra. Osredotočila sem se na njegovo uporabo in na konkretnih primerih fluorescirajočih snovi preizkusila njegove zmožnosti in delovne značilnosti. Najprej sem s pomočjo literature in podatkov o karakterističnih valovnih dolžinah vzbujevalnih in emisijskih maksimumov poiskala ter izbrala pet snovi, ki fluorescirajo in so dostopne v običajnem analiznem laboratoriju. Kriteriji izbire so bili predvsem to, da se maksimumi pojavijo v čim širšem območju svetlobnega spektra. Kot modelne snovi sem izbrala riboflavin, fluorescein, benzojsko, folno in salicilno kislino. Po izbiri snovi sem v literaturi poiskala podatke o pripravah raztopin in pogojih merjenja. Raztopino riboflavina sem pripravila v 5% ocetni kislini, fluoresceina v 0,1% amonijaku, benzojske kisline v 0,01 mol/L HCl, salicilne kisline v raztopini ocetne kisline in kloroforma ter folne kisline v raztopini fosfatnega pufra in 0,1 mol/L vodni raztopini amonijaka. Za izbrane snovi sem najprej posnela absorpcijske spektre z molekularnim absorpcijskim spektrometrom, nato emisijske in vzbujevalne spektre z molekularnim fluorescenčnim spektrometrom. Zatem sem po enakih postopkih pripravila raztopine in posnela še spektre z modularnim sistemom, katere sem kasneje primerjala s tistimi dobljenimi s konvencionalnimi instrumenti. S pomočjo vseh instrumentov sem preizkusila obnašanje v širšem območju spreminjanja parametrov. Z uporabljenimi sestavnimi komponentami sem uspela z modularnim sistemom določiti emisijske maksimume za dve snovi, ki emitirata svetlobo nad 500 nm (riboflavin in fluorescein). Za ostale pa to ni bilo mogoče. Absorpcijske maksimume je bilo mogoče določiti za vse modelne snovi. Pri primerjavi valovnih dolžin maksimumov med instrumenti sem ugotovila, da do velikih odstopanj ne pride. Prav tako se eksperimentalni podatki dobro ujemajo z literaturnimi podatki. Intenzitete pa zaradi drugačne zgradbe instrumentov težko primerjam.

• Jezik: Slovenski jezik
• Ključne besede: absorbanca, fluorescenca, spektrometer, emisija, spekter
• Vrsta gradiva: Diplomsko delo/naloga
• Tipologija: 2.11 - Diplomsko delo
• Organizacija: FKKT - Fakulteta za kemijo in kemijsko tehnologijo
• Leto izida: 2023
• PID: 20.500.12556/RUL-149726
• COBISS.SI-ID: 165257987
• Datum objave v RUL: 08.09.2023

Sekundarni jezik

• Jezik: Angleški jezik
• Naslov: Modular molecular fluorescence spectrometer operational qualification

Izvleček

In my undergraduate thesis, I evaluated the behaviour of modular molecular fluorescence spectrometer. I focused on its use, so I tested its capabilities and working characteristics on concrete solution samples. Firstly, with the help of literature and data about characteristic wavelengths of emission and excitation maxima, I searched and selected five substances that are fluorescent and are accessible in ordinary analytical laboratory. The criteria for choosing were mainly that their maxima appear in wider range of spectrum. So, I chose riboflavin, fluorescein, benzoic, folic and salicylic acid as sample solutions. After choosing the substances, I have sought for information on the preparation of solutions and measurement conditions in the literature. Later I prepared solutions of riboflavin in 5% acetic acid, fluorescein in 0,1% ammonia, benzoic acid in 0,01 mol/L HCl, salicylic acid in a solution of acetic acid and folic acid in a solution of phosphate buffer and 0,1 mol/L aqueous solution of ammonia. For the selected substances, I first recorded absorption spectra on UV-VIS spectrometer, after that emission and excitation spectra on molecular fluorescence spectrometer. Then, following the same procedures, I prepared the solutions and recorded spectra on modular system, which I could later compare with those obtained on conventional instruments. On all of them, I tested the behaviour in wider range of changing the parameters. With the components used, I managed to determine the emission maximum on modular system for two substances that emit light above 500 nm (riboflavin and fluorescein). For the rest, this was not possible. But on the other side, I could determine absorption maxima for all model substances. When comparing wavelengths of the maximum between different instruments, I found out that there is no big difference and same when comparing the results with literature. But the comparison of intensities is difficult due to different design of instruments.

• Ključne besede: absorbance, fluorescence, spectrometer, emission, spectrum