Trace determination of benzoic acid in food samples using magnetic-chitosan nano-based particles functionalized with Folic acid

Benzoic acid and its salt are widely used as preservatives in foods, beverages, toothpastes, mouthwashes, dentifrices, cosmetics and pharmaceuticals [1]. Efficient extraction and determination of hazardous pollutants (e.g. organic aromatic compounds and inorganic heavy metals) is a significant concern to ecosystem and human health due to their high toxicity and very slow biodegradation. Hydroxybenzoic acids are now extensively studied as organic pollutants on the basis of their potential toxicities on plants, animals and human beings [2,3]. These preservatives are allowed by legislation that establishes the maximum permitted concentrations in each type of food. However, their presence atlevels higher than permitted safety levels can be harmful to human health. Some adverse effects, such as metabolic acidosis, convulsions, hyperpnoea and allergic reactions in experimental animals and in humans are described [4]. In this study, a magnetic chitosan functionalized with folic acid (MCN-FA) was synthesized and applied as nano-adsorbent in magnetic dispersive micro solid phase extraction (MD-μSPE) method for preconcentration and determination trace amounts of benzoic acid. The properties of the as-synthesized MCN-FA were characterized by Fourier-transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), Vibrating sample magnetometer (VSM) and Field emissionscanning electron microscope (FE-SEM). The main effective parameters on the MD-μSPE, including solution pH, dose of adsorbent, adsorption time and temperature were investigated, and optimized by using a central composite design [5]. Under the optimum conditions, linear dynamic rang (LDR), limit of detection (LOD), and relative standard deviation (%RSD) were 10-650 ng mL-1, 2.75 ng mL-1 and 4.4%, respectively. Finally the proposed method was successfully applied for monitoring andquantification of benzoic acid in food samples.

کلیدواژه ها:

Benzoic acid ، Magnetic chitosan ، Dispersive micro solid phase extraction ، Central composite design ، Food samples