Optimizacija ekstrakcije DDT iz tal

Hrovat, Jaša (author), Prosen, Helena (mentor)

DDT se je v preteklosti uporabljal kot insekticid v kmetijstvu. Leta 1945 so se začeli porajati prvi dvomi o njegovi škodljivosti. Postopoma so ga prepovedali v vseh državah, dovoljen je zgolj za preprečevanje širjenja malarije. Zaradi svoje lipofilne narave se je do danes zadržal v okolju. Za diplomsko delo sem primerjal dve ekstrakcijski tehniki za ekstrakcijo tega pesticida in njegovega metabolita DDE iz tal. Primerjal sem Soxhletovo in ultrazvočno ekstrakcijo. Ekstrakte sem analiziral s pomočjo GC-ECD detektorja, ki je selektiven za halogenirane spojine. Ugotovil sem, da ekstrakcija DDT pri obeh metodah poteka z višjim izkoristkom kot ekstrakcija DDE. Temu bi lahko botrovala temperatura ekstrakcije, saj se lahko med zemljo in pesticidom tvorijo močnejše intramolekularne vezi, ki jih težje prekinemo. Svoje rezultate sem primerjal tudi s podatki drugih raziskav, pri čemer sem ugotovil, da so ekstrakcije izvajali dlje časa, čemur botruje tudi višji izkoristek.

• Language: Slovenian
• Keywords: DDT, Soxhletova ekstrakcija, ultrazvočna ekstrakcija
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Year: 2022
• PID: 20.500.12556/RUL-139929
• COBISS.SI-ID: 128600835
• Publication date in RUL: 08.09.2022

Secondary language

• Language: English
• Title: Optimization of DDT extraction from soil

Abstract

DDT was used in the past as an insecticide in agriculture. In 1945, doubts began to arise about its use. It was gradually banned in all countries, it is currently only allowed to prevent the spread of malaria. Due to its lipophilic nature, it has remained in the environment until today. For my thesis, I compared two extraction techniques for the extraction of this pesticide and its metabolite DDE from soil. I compared Soxhlet and ultrasonic extraction. I analyzed the extract using a GC-ECD detector, which is selective for halogenated compounds. I have found that the extraction of DDT with both methods gives a higher yield than the extraction of DDE. The temperature of the extraction could contribute to this, since stronger intramolecular bonds can form between the soil and the pesticide, which are more difficult to break. I also compared my results with the data of other studies, where I found that the extractions were carried out for a longer time, which is also supported by the higher yield.

• Keywords: DDT, Soxhlet extraction, ultrasound extraction