Dados do Trabalho

Título

DETERMINATION OF PESTICIDES IN AÇAÍ-BASED FOOD PRODUCTS: AN APPROACH USING POLYMERIC IONIC LIQUID-BASED SPME SORBENT COUPLED TO GC-MS

Introdução

Açaí cultivation has been increasing due to the expansion of its high consumption in Brazil and foreign markets, especially in the United States, the largest consumer of AFPs outside of Brazil. For the first time, a method for the simultaneous analysis of pesticides in AFPs was developed using polymeric ionic liquid-based sorbent coatings in solid-phase microextraction coupled to gas chromatography–mass spectrometry.

Material e Métodos

For this, five different polymeric ionic liquid (PIL) fibers were synthesized, each tailored with different functional groups of the ionic liquid (IL) monomer and crosslinkers. Additionally, three commercial fibers were employed for comparison purposes. Seven pesticides authorized by the Brazilian Health Regulatory Agency (ANVISA) for application in açaí cultivation were analyzed. The conditions employed to extract pesticides from AFPs were optimized using direct immersion-solid-phase microextraction through a central composite rotatable design, optimizing the following variables: extraction temperature, extraction time, and concentration of NaCl. In addition, the Derringer and Suich design was applied to select the best extraction conditions.

Resultados e Discussão

Among the studied fibers, the PIL fiber using the IL monomer 1-vinyl-3-octylimidazolium bis(trifluoromethanesulfonyl)imide and the crosslinker 1,12-di(3-vinylimidazolium)dodecane dibis[(trifluoromethyl)sulfonyl]imide was selected to conduct the extraction and analytical validation. This choice was based on the ability of this fiber to exhibit the highest extraction efficiency for the pesticide with the lowest limit of detection. A PIL-SPME-GC-MS method was employed for analytical validation and the study of pesticide occurrence in twenty-five samples. including AFPs and pure açaí. The samples were arbitrarily purchased in Brazil (n = 15) and the United States (n = 10). The proposed methods presented calibration curves with correlation coefficients ≥ 0.989, limit of detection ranging from 3 to 100 µg kg−1, appropriate recovery with values between 70% and 88%, and good precision (≤12% RSD), under repeatability and within-laboratory reproducibility conditions. Matrix effects ranged from -87% to 22%. Pesticides were found in seven samples. S-Metolachlor was quantified in four samples at concentrations of 10, 12, 10, and 13 µg kg⁻¹. Thiabendazole was detected (≤ LOQ) in two samples. Additionally, fluxapyroxad was detected in two samples.

Conclusão

The method's suitability was demonstrated for future monitoring of complex samples, such as foodstuffs.