Use of response surface methodology in the optimization of the microwave assisted extraction method for determination of multielements in Brassica oleracea var. capitata (cabbage) samples

In this study, the response surface methodology was used by the central composite design in development of a microwave-assisted extraction method to build a model based on four factors including power, extraction time, temperature and volume of extraction solvent for the extraction of iron, copper, manganese and zinc from cabbage (Brassica oleracea var. capitata). This model was applied to determine the optimum conditions for desirable response and to evaluate the influences experimental factors. A multiple response function (Y-m) was used to explain the experimental conditions of the target element. Optimum conditions were found to be 201 (W), 60 degrees C, 10 min and 4 mL for power, temperature, time and volume of nitric acid, respectively. High regression coefficient between the variables and the response (R-2 = 0.993) showed excellent evaluation of experimental data by polynomial regression model. The RSD% for purple and white cabbage was 1.3 and 1.5 %, respectively. The developed procedure was then used for the extraction and determination of these elements in the some cabbage samples.