Extração do inseticida carbaril em casca e polpa de banana

Abstract

In Brazil, the banana is considered the second most cultivated fruit and has significance for Brazilians, not only for its nutritional value, but for its accessibility. Carbaryl is a pesticide indicated and regulated by the National Health Surveillance Agency for banana cultivation. Although it is authorized for this culture, its inappropriate use, as it is highly toxic, can cause intoxication in humans and / or cause death, depending on the degree of exposure. The objective of this work was to verify the applicability of solid-liquid extraction with low temperature partition (SLE-LTP) and analysis by high-performance liquid chromatography to determine carbaryl in the individual parts of the banana, taking into account its stage of ripeness, homogenization methods and time for sample fortification. The matrices were worked in their two stages of development, that is, ripe and green, being separated into: green peel, green pulp, ripe peel and ripe pulp. The samples were crushed to homogenize the individual parts, and then 1.0000 g of sample was weighed for each tube. For the ESL-PBT technique, the methodology proposed by Goulart et al., (2010) was used. 200 mg L-1 of standard solution of carbaryl was used to fortify each sample. Some fortified samples waited 3 h for extraction after fortification. In the extraction process, 2 mL of water and 4 mL of the Acetonitrile solvent (ACN) were added as an organic solvent. This system was agitated. When the ultrasonic bath was used, the time was 10 min. When vortexing was used, the time was 1 minute. After this stage, the system was frozen for 3 hours (low temperature partition) and 1 mL of the supernatant was removed for further chromatographic analysis. In this work, it was found that the analyzed individual parts of the banana (pulp and peel) regardless of the method used (fortification and agitation), and its ripeness status (green and ripe) do not differ by their statistical values by the t test of Student, at the 5% significance level. Regarding the fortification time, there is no need to use the 3-hour interval, which makes the SLE-LTP faster. Regarding the methods for homogenizing the systems, in all tests performed, agitation in vortex or in an ultrasonic bath, did not present any differences between them, due to the agility in the preparation of samples, ultrasonic bathing is recommended. The percentages of recovery obtained with the use of the SLE-LTP technique that was applied aiming at the determination of carbaryl in banana (peel and pulp), regardless of the treatment, remained with percentages within the parameters accepted by the inspection agency in Brazil, which establishes percentages of recoveries in the range of 70 to 120%.