Increased use of pesticides has greatly increased yields and raised the quality level of life. In my dissertation I have focused on neonicotinoids, which are considered systemic insecticides and act as agonists of nicotine acetylcholine receptors.
The observed group of analytes is considered to have a high solubility in water, which leads to leaching into surface waters and consequently a constant presence in soil, dust, underground waters, non-target plants and their products. As a result, they can have a negative impact on living organisms, as shown by research in recent years on the impact of neonicotinoids on bees. Today, only acetamiprid, flonicamide and imidacloprid are registered in the Slovenian database of phytopharmaceutical products. The use of others from this group is prohibited.
The aim of the work was to determine the presence of five neonicotinoids (acetamiprid, clothianidin, imidacloprid, thiacloprid, thiamethoxam) in beer. In the process of sample preparation, I used solid phase extraction and HPLC-DAD to analyze and separate the analytes. I randomly chose five beers available on Slovenian store shelves and from different parts of the world.
Based on average retention times, the results of the analysis of beers initially indicated the presence of thiamethoxam and clothiadinin, but I rejected the hypothesis of the possible presence of these neonicotinoids based on differences in absorption ratios of peaks in the chromatograms of compounds and standard solutions. The spectra of the eluted compounds and the standard compounds also differed from each other, which further confirmed my decision. Therefore, the presence of analyzed compounds was not confirmed in the analysed beers.
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