Liquid-phase microextraction of ascorbic acid in food and pharmaceutical samples using ferrofluid-based on cobalt ferrite (CoFe2O4) nanoparticles

Abstract

Quantitation of ascorbic acid is extremely desired in the food, cosmetic, and pharmaceutical samples. In this study, liquid-phase microextraction using ferrofluid (LPME-FF) based on the cobalt ferrite nanoparticles (CoFe2O4) coupled with a green, precise, accurate, and robust spectrofluorometric approach was used for extraction and determination of ascorbic acid. The procedure is based on the reaction between ascorbic acid (AA) and methylene blue (MB) as an inexpensive and readily available fluorescence quenching reagent. The native fluorescence intensity of MB was quenched using ascorbic acid. The CoFe2O4 magnetic nanoparticles were synthesized and confirmed by Fourier transform infrared (FT-IR) spectroscopy, vibrating sample magnetometer (VSM), field emission scanning electron microscopy (FE-SEM), and energy dispersive X-ray spectroscopy (EDXS). Three parameters of pH, ferrofluid volume, and ultrasonic time were selected as influential factors on the process and optimized by central composite design (CCD). Under optimal conditions, linear range, detection limit, and the relative standard deviation were obtained 0.26–5.70 μM, 0.074 μM and, 2.0 %, respectively. Finally, the proposed method was successfully employed for the quantification of ascorbic acid in real samples of lemon juice, orange juice, and vitamin C tablets.