Verificação da lineridade e efeito matriz do herbicida ametrina em milho (zea mays l.) e posterior aplicação em amostras reais utilizando o método quechers-cg-em.

Abstract

For years, analytical methods for determining agricultural pesticides in food have been rapidly developed and validated to optimize traditional methods, which were characterized by slowness, high cost, and a large volume of solvent. The complexity of food properties complicates the quantification of agricultural pesticides, necessitating efficient sample preparation before analysis to remove as many interferents as possible. The QuEChERS method demonstrates versatility and robustness, allowing for its execution in various laboratories. Its practicality and reliability have been evidenced by numerous citations in scientific papers since its development. The results are even more satisfactory when coupled with Gas Chromatography-Mass Spectrometry (GC-MS). The effectiveness of this extraction and detection method for investigating agricultural pesticides in food is important for both the biotic and abiotic segments of the planet. In this context, this study investigated some analytical validation parameters, such as linearity, which exhibited a correlation coefficient close to 0.99 for calibration curves prepared in pure solvent and in the extract of the matrix itself. The matrix effect was over 400%, and the method was subsequently applied to real samples, revealing no presence of ametryn or any other pesticides in the investigated samples. The limits of detection (LODs) and quantification (LOQs) were 30 μg L-1 and 100 μg L-1

, respectively, for both curves (in solvent and in the corn matrix). Future perspectives include the study of recovery, as it was not possible to verify it due to the short time frame and unforeseen events during the research. A qualitative evaluation using the scanning method and comparing the obtained spectra with the NIST library revealed the presence of some organic contaminants, with mass spectrum similarities of 32.5% and 23.8% for Dibutyl Phthalate and Oxymetazoline, respectively.