Extração sólido-líquido com partição à baixa temperatura para análise de carbaril em banana prata (Musa sapientum)

Abstract

For years the chemicals have been used in the cultivation of various food crops for the control of pests and diseases that affect agricultural production. Increasingly, it is necessary to monitor the use of these pesticides, to evaluate if farmers are using these products in a conscious way, respecting the necessary care and acceptable limits for each type of crop. Several techniques have been developed to evaluate the presence of pesticides in food matrices. Considering the need for increasingly practical, efficient, less polluting and low-cost methods, some researchers used the Low Temperature Partition Solid-Liquid Extraction (LSE-LTP) method for the analysis of pesticides in foods of plant origin, because it has high applicability, and selectivity. Banana inBrazil is planted and marketed in all states, both for its high nutritional value and low cost. In the region of the municipality of Itumbiara, there are fruit plantations, and therefore it was chosen as a matrix for this research. Thus, the objective of this work was to optimize the LSE-LTP method for determining carbaryl in bananas and later with the verification of the results and definition of the best test, to analyse the presence of carbaryl in bananas in the Itumbiara-GO trade and plantation. For optimization of the analysis parameters, a complete 2³ factor planning was employed: relation between water volume and solvent extractor, saline concentration and type of solvent extractor. For the separation, identification and quantification of carbaryl, High Performance Liquid Chromatography with UV detector (HPLC-UV) was used. From the study of the results obtained by the analyses, it was verified that the research allowed the optimization of the method and proved efficient for the analysis of the banana carbaryl, since LSE-LTP has good selectivity, is easy to run, simple and low-cost. In the optimization, test 2 (two) was chosen, with extraction efficiency of 108.18%, with Factor 1 (Relation of water volume and extractor solution of 1:2), thus using a volume of water of 2 mL and solvent of 4 mL; Factor 2 (without addition of NaCl) and Factor 3 (ACN as solvent extractor). In addition, the value of the rate of recovery of the surveyed pesticides (111.4%) was within parameters established for the analysis of residues by national and international bodies. Experiments with banana samples from plantations and greens in the Itumbiara region using the LSE-LTP method optimized in this work and subsequent analysis by HPLC-UV did not show the presence of carbaryl. Samples of bananas marketed in two supermarkets in the city of Itumbiara and region were also analysed and samples from supermarket 2 did not show carbaryl, However, in supermarket 1 there was the presence of pesticides in concentration (0.49 mg/kg), almost three times the maximum allowed limit. Research such as this is extremely important, not only to raise awareness among farmers of the causes of the indiscriminate use of pesticides on the short and long-term effects on human and environmental health, but also for knowledge of society, about the quality of what is being consumed.