| چکیده انگلیسی مقاله |
Extra consumption of synthetic food dyes has some side effects such as DNA damage, allergy, and asthmatic reactions, carcinogenesis, and hyperactivity. So acceptable level of dyes must be controlled and is necessary to develop reliable analytical methods for extraction and determination of these chemicals in daily use products [1]. In this research, Fiber-in-tube solid phase microextraction (FIT-SPME) followed by HPLC-UV for extraction and determination of acidic red dyes (Amaranth, Ponceau 4R, Allura red, Carmoisine, and Erythrosine) in juice samples. There are some advantages in this device such as reduction of back pressure during extraction and desorption, higher surface area of the coating, and also smaller void volume of the extraction tube [2]. In this way, the fibers were fabricated with a composite of chitosan and polyvinyl alcohol by electrospinning method to achieve nanofibers with high surface area and porosity. Non-toxicity, biodegradability, biocompatibility, and hydrophilicity led to the use of chitosan in various fields. Moreover, there are amino and hydroxyl groups in its structure that make it as an inexpensive and recyclable bio sorbent for organic dyes by electrostatic interaction. Pure chitosan has a limited electrospinnability so to achieve the fine fibers, it should be blending with some co-polymers such as PVA. It is a synthetic polymer that is water-soluble, chemical resistive, non-toxic, biocompatible, and biodegradable [3]. The effective parameters on the extraction efficiency including desorption solvent type, extraction time, extraction flow rate, desorption flow rate, and desorption solvent volume were optimized by one variable at a time and experimental design approaches. Response surface methodology (RSM) is a statistical technique to display the coherency between variables, reduction of experiments number, materials, time and costs [4]. RSM based on an orthogonal and rotatable central composite design (CCD) in five levels was employed to optimize the quantitative factors. Due to the large number of experiments, they were divided into 3 blocks and carried out in 3 different days. Under the optimum conditions, the method showed good dynamic linearity in the range of 1.00-750.00 µg L-1 with LODs in the range of 0.30-7.57 µg L-1 and coefficient of determinations higher than 0.9943. The intra-day and inter-day RSDs were in the range of 2.5-9.5 % and 7.3-12.7 % respectively. Finally, this technique was applied for extraction and determination of analytes in beverages samples such as pomegranate, red grape, and sour cherry juices with acceptable and satisfying results. |
