A green approach for in-tube solid phase microextraction of acidic red dyes from juice samples using chitosan/poly vinyl alcohol electrospun nanofibers

Abstract

In this research, a green approach of filled in-tube solid phase microextraction (FIT-SPME) followed by HPLC-UV was introduced for extraction and determination of acidic red dyes (Amaranth, Ponceau 4R, Allura red, Carmoisine, and Erythrosine) in juice samples. In this way, stainless-steel wires were coated with chitosan as a natural polymer and polyvinyl alcohol as a safe co-polymer by electrospinning method, to achieve nanofibers with high surface area and porosity. Then, all fibers were put inside the lumen of a stainless-steel tube to make the extraction medium. 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. Under the optimum conditions, the method showed good dynamic linearity in the range of 1.0–750.0 μg L−1 with LODs in the range of 0.3–7.6 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 to the extraction and determination of the analytes in different beverage samples such as pomegranate, red grape, and sour cherry juice with acceptable and satisfying results.