Trace Determination of Vitamins B3 in Food Samples Based on Graphene oxide - cobalt ferrite Nanocomposite and Antibacterial assay

Vitamin B3 (Niacin) is one of the B group vitamins that can be found in two forms, nicotinamide and nicotinic acid, and is essential for living cells. Vitamin B3 is not stored in the body and must be ingested with food. The recommended amount of this vitamin for humans is 12-16 mg day-1 [1]. Excessive consumption of vitamin B3 can cause symptoms such as skin itching, headache, stomach ulcer or even liver damage [2]. Therefore, the determination of vitamin B3 in real samples is crucial to control and prevent the symptoms caused by its unauthorized consumption. So, as a result, it is necessary to utilize a sensitive and reliable method to determine vitamin B3. In this work, magnetic cobalt ferrite/graphene oxide (CoFe2O4/GO) adsorbent was synthesized and characterized by Fourier transform infrared (FT-IR) spectroscopy, vibrating sample magnetometer (VSM), field emission scanning electron microscopy (FE-SEM) and X-Ray diffraction (XRD). Magnetic dispersive micro-solid phase extraction (MD-μSPE) consisting of CoFe2O4/GO nanocomposite coupled with a green, precise, accurate, and robust spectrofluorometric approach was used for preconcentration, extraction and determination of vitamin B3. Four parameters of pH, adsorbent dose, temperature and sonication time were selected as effective factors on the process and optimized by central composite design (CCD) [3]. Under optimized conditions, the linear range, limit of detection, and the relative standard deviation (R.S.D) were obtained 10–900 ng mL-1, 5.64 ng mL-1 and 4.24 % respectively. Finally, the proposed method was successfully applied for preconcentration and determination of vitamin B3 in food samples. In addition, antibacterial activity of the CoFe2O4/GO nanocomposite was evaluated on Escherichia coli and Staphylococcus aureus bacteria.