C in the presence of vitamin B-9 in food and pharmaceutical samples

Synthesis and application of NiO-multiwall carbon nanotube nanocomposite (NiO/MWCNTs) and 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim]BF4) in the carbon paste matrix as high sensitive sensors for voltammetric determination of vitamin C have been reported. The oxidation peak potential of vitamin C at the surface of the ([Bmim]BF4) NiO/MWCNT carbon paste electrode (NiO/MWCNTs/([Bmim]BF4/CPE) appeared at 440 mV, which was about 200 mV lower than the oxidation peak potential at the surface of the simple carbon paste electrode under a similar condition. Also, the oxidation peak current was increased for about 3.7 times at the surface of NiO/MWCNTs/([Bmim]BF4/CPE compared to carbon paste electrode. At an Optimum,condition (pH 7.0), the two peaks are separated ca. 0.44 and 0.85 V for vitamin C and vitamin B-9. This point shows that vitamin C can be determined in the presence of vitamin B-9. The linear response range and detection limit were found to be 0.1-1000 mu M and 0.06 mu M, respectively. The proposed sensor was successfully applied, for the determination of vitamin C in food and drug samples. (C) 2016 Elsevier B.V. All rights reserved