Dispersive solid-phase microextraction with arginine-functionalized magnetic nanocomposite as the sorbent for separation and preconcentration of aspartame and optimization using response surface methodology

Abstract

In this study, the surface of magnetic dialdehyde starch nanocomposite has been modified with arginine amino acid (Arg) and employed as an adsorbent for the enrichment of aspartame (ASP) in different real samples. Magnetite dispersive solid-phase microextraction (MDSPME), which had been combined with spectrophotometry, has been used to determine the extracted aspartame. The Plackett–Burman design has been employed to investigate the influence of main parameters including the amount of salt, sample volume, amount of sorbent, dispersive solution volume, desorption, and extraction time, and central composite design has been used to obtain the optimum condition in MDSPME method. Under optimum conditions, 15 ml of sample volume, 1.5 ml of ethanol as dispersive solvent, 10 min of extraction time, 15 min of desorption time, 10 mg of sorbent, and 0 w/v % of salt, the calibration graph has been observed to be linear in a concentration range of 2–15 µg ml−1, while the limit of detection has been 0.064 µg ml−1. The relative standard deviations of 3.64 and 4.12 have been obtained at 8 µg ml−1 level of aspartame for the intra- and inter-day analysis. In addition, the enrichment factor has been about 128. This procedure has been successfully utilized for distinguishing the existing aspartame in two kinds of beverage that had been procured from local markets and drinkable water.