Application of central composite design in parameters optimization of nano-structured supramolecular solvent based on liquid-liquid microextraction for determination of total lead in food, vegetables, grilled meat products, and water samples

Abstract

The main aim of this research article is to develop a new sample preparation method based on liquid-liquid microextraction using nanostructured supramolecular solvent for analysis of total lead in food, vegetables, grilled meat products, and water samples. Optimization of important microextraction parameters was optimized using central composite design based on response surface methodology. Sulfadiazine provided the complexation of Pb(II) ions in the aqueous solution. Prior to optimization step, three supramolecular solvents were prepared and tested for analysis of Pb(II). Analysis of variance was used to investigate the main effects of microextraction parameters and their interactions and optimum parameters were selected based on the model of experimented results. Using optimized conditions, the working range, coefficient of determination, limit of detection, and enhancement factor of the developed method were found to be 0.5–400 μgL−1, 0.997, 0.15 μg L−1 and 126, respectively. The validation of the developed method was confirmed with certified reference material. Spiked recovery tests were also performed on food, vegetables, grilled meat products, and water samples to determine the method's accuracy and applicability to the selected samples. The percent recoveries for Pb(II) ions were between 91 and 104%, and percent relative standard deviation values were below 3.8% indicating acceptable precision and accuracy. The developed method represents a promising choice for a green sample preparation procedure for determination of total Pb in real samples.