Desenvolvimento de método analítico para determinação de fitoesteróis em óleo vegetal assistida por ultrassom

Abstract

This work sought to optimize experimental conditions for determination of phytosterols through the methodology of answer surface, kind Box- Behnken, using radiation in the ultrasound frequency as an energy source and validate this new method. The variables were investigated in three levels -1,0, and +1: amount of sample, volume of ethanolic solutions of KOH added and ultrasound time. The new method developed was evaluated from analytical parameters of validation selectivity, linearity, linear dynamic range, precision “intra-day”, accuracy and detection limits and quantification. The optimized conditions presented to a stigmasterol values of 0,25 g of oil, 2,5 mL of basic solution and 300 seconds for ultrasound time. Already for β-sitosterol the optimal point they were obtained 0,25 g of oil, 5,40 mL of basic solution and 300 seconds for ultrasound time. In front of the obtained results and the analysis performed by parameters, it can be said that the method it has the same efficiency of the traditional, and and also significantly reduced analysis time of 3600 seconds for 300 seconds in the saponification step as compared to the traditional method.