Določanje neonikotinoidnih pesticidov v pelodu

Globočnik, Maja (author), Prosen, Helena (mentor)

V magistrskem delu smo želeli razviti metodo za določanje petih neonikotinoidov v pelodu. Izbrali smo acetamiprid, imidakloprid, klotianidin, tiakloprid in tiametoksam. Določanje smo izvedli z metodo HPLC-DAD, ki je že bila predhodno optimizirana za določevanje neonikotinoidov in smo samo preverili njeno ustreznost. Za pripravo vzorca smo uporabili metodo ekstrakcije na trdno fazo (SPE), ki jo je bilo potrebno optimizirati. Dokazali smo, da aceton in acetonitril znatno vplivata na izkoristek ekstrakcije, v kolikor sta v začetni raztopini vzorca prisotna v vsaj 10 % (v/v). Z zniževanjem koncentracije začetne standardne raztopine smo ocenili mejo določitve in mejo zaznave naše metode SPE-HPLC-DAD. Kromatogrami vzorca peloda z optimizirano izvedbo SPE so še vedno bili zelo kompleksni, torej nismo uspeli popolnoma izničiti vpliva matrične raztopine in ekstrahirati samo neonikotinoidov. Vseeno smo s pomočjo referenčnih UV spektrov standardnih raztopin dokazali uspešno ekstrakcijo neonikotinoidov iz vzorcev, onesnaženih s teoretičnim masnim deležem neonikotinoidov 2 μg/g in 0,5 μg/g. Maksimalni izkoristek je znašal 96,1 % in sicer pri acetamipridu in masnem deležu 0,5 μg/g. Na koncu smo še prilagodili tematiko magistrske naloge za predstavitev njenega manjšega dela v obliki učne ure, ki jo lahko izvedemo v srednjih šolah pri pouku kemije. Zasnovali smo eksperiment s TLC, pri katerem se dijaki seznanijo s kromatografijo, v nadaljevanju pa sledi uvedba novega znanja ali utrjevanje pojmov iz sklopa Uvod v varno eksperimentalno delo.

• Language: Slovenian
• Keywords: pelod, neonikotinoidi, HPLC-DAD, SPE, TLC
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Year: 2023
• PID: 20.500.12556/RUL-145764
• COBISS.SI-ID: 153410563
• Publication date in RUL: 12.05.2023

GLOBOČNIK, Maja, 2023, Določanje neonikotinoidnih pesticidov v pelodu [online]. Master’s thesis. [Accessed 13 June 2025]. Retrieved from: https://repozitorij.uni-lj.si/IzpisGradiva.php?lang=eng&id=145764

Secondary language

• Language: English
• Title: Determination of neonicotinoid pesticides in pollen

Abstract

In this study, we aimed to develop a method for determination of five neonicotinoids in pollen. We chose acetamiprid, imidacloprid, clothianidin, thiacloprid and thiamethoxam. Determination was performed with HPLC-DAD, which has been previously optimised for analysis of neonicotinoids, we have only checked if it is still viable. Solid-phase extraction (SPE) was used as a pre-treatment method of the sample and needed to be optimised. We have proved that acetone and acetonitrile have significant impact on the recovery of extraction if present in at least 10% (v/v) in starting solution of sample. Limit of detection and limit of quantification of the developed method SPE-HPLC-DAD were estimated by lowering concentrations of standard solutions. Chromatograms of pollen samples were very complex, which means we have not succeeded to extract only neonicotinoids. Nevertheless, we have confirmed a successful extraction with reference UV spectra of standard solutions in artificially polluted samples with theoretical mass percent 2 μg/g in 0.5 μg/g. Maximum recovery was 96.1% and was achieved for acetamiprid at theoretical mass percent 0.5 μg/g. In the very end, we have adjusted the subject of this study to present a smaller part of it as a matter of a lesson in high school. First part of the lesson consists of getting acquainted with chromatography by TLC experiment, which is followed by introduction of new knowledge or revising prior knowledge from the topic Introduction to safe experimental work.

• Keywords: pollen, neonicotinoids, HPLC-DAD, SPE, TLC