magistrsko delo
Maksimiljan Dekleva (Author), Helena Prosen (Mentor), Iztok Turel (Thesis defence commission member), Mitja Kolar (Thesis defence commission member), Danjela Kuščer (Co-mentor)

Abstract

Neonikotinoidi so sistemski pesticidi, katerih uporaba se je v devetdesetih letih prejšnjega stoletja naglo razširila. Negativne posledice njihove uporabe so se pokazale šele s precejšnjim zamikom. Dandanes se dobršen del kemijske analitike ukvarja z razvojem metod za njihovo določanje, vključujoč nekatere konvencionalne separacijske tehnike in naprednejše načine, kot so elektrokemijski senzorji. V okviru eksperimentalnega dela sem v modelni raztopini testiral elektrokemijske lastnosti tiskanih kvazireferenčnih elektrod iz srebrove paste in tiskanih protielektrod iz paste na osnovi platine. Testiral sem tiskane delovne elektrode na osnovi različnih ogljikovih materialov. Za optimalno se je izkazala mešanica grafita in stekla v razmerju 75:25. Na podlagi rezultatov elektrokemijskih meritev je bil s tehniko sitotiska pripravljen trielektrodni sistem, ki se je izkazal za znatno izboljšavo komercialnih sitotiskanih elektrod na osnovi ogljika. Optimiziral sem vrsto materiala in količino nanosa za modifikacijo površine delovne elektrode, z glavnim ciljem izboljšanja elektrokemijskega odziva pri določanju neonikotinoidnih pesticidov. Za tri pesticide sem dosegel dobro ponovljivost v širokem linearnem območju z mejami zaznave 2,68 – 4,40 mg/L. V zadnji fazi eksperimentalnega dela sem optimiziral uveljavljeno metodo HPLC-MS/MS, ki je v primerjavi z elektrokemijskimi meritvami precej bolj dolgotrajna, poraba topil in cena pa sta višji. Tudi tu sem dosegel dobro ponovljivost v širokem linearnem območju, hkrati pa so tudi meje zaznave precej nizke, in sicer 0,12 – 86 g/L.

Keywords

neonikotinoidi;neonikotinoidni pesticidi;voltametrija;senzorji;elektrode;sitotisk;visokoločljivostna tekočinska kromatografija;masna spektrometrija;HPLC-MS/MS;magistrska dela;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UL FKKT - Faculty of Chemistry and Chemical Technology
Publisher: [M. Dekleva]
UDC: 543.552(043.2)
COBISS: 128777731 Link will open in a new window
Views: 103
Downloads: 35
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Other data

Secondary language: English
Secondary title: Optimization of materials and testing of working electrode for a electrochemical sensor for the determination of neonicotinoids
Secondary abstract: Neonicotinoids are systemic pesticides, the use of which rapidly expanded in the 1990s. The negative consequences of their use only became apparent after a considerable delay. Today, a good part of chemical analysis is concerned with the development of methods for their determination, including some conventional separation techniques and more advanced methods such as electrochemical sensors. As part of the experimental work, I tested the electrochemical properties of printed quasi-reference electrodes made of silver paste and printed counter electrodes made of platinum-based paste in a model solution. I tested printed working electrodes based on different carbon materials. A mixture of graphite and glass in a ratio of 75:25 proved to be optimal. Based on the results of the electrochemical measurements, a three-electrode system was prepared using the screen-printing technique, which proved to be a significant improvement over commercial carbon-based screen-printed electrodes. I optimized the type of material and the amount of deposition to modify the surface of the working electrode, with the main goal of improving the electrochemical response for the determination of neonicotinoid pesticides. For the three pesticides, I achieved good reproducibility over a wide linear range with detection limits of 2.68 – 4.40 mg/L. In the last phase of the experimental work, I optimized the comparative method of HPLC-MS/MS, which, compared to electrochemical measurements, is much more time-consuming, and the consumption of solvents and the price are higher. Again, I achieved good repeatability over a wide linear range, while the detection limits are also quite low, at 0,12 - 86 g/L.
Secondary keywords: neonicotinoids;voltammetry;sensors;sreen-printing;Elektroanaliza;Univerzitetna in visokošolska dela;
Type (COBISS): Master's thesis/paper
Study programme: 1000375
Embargo end date (OpenAIRE): 1970-01-01
Thesis comment: Univ. v Ljubljani, Fak. za kemijo in kemijsko tehnologijo, smer Kemija
Pages: 77 str.
ID: 16401027