Simple and reliable determination of B group vitamins in various food matrices with the use of the voltammetric sensor based on Ni-zeolite/carbon black nanocomposite

In this work, a low-cost and highly selective voltammetric method for the determination of vitamin B2 (VB2), B9 (VB9), B12 (VB12), and B3 (VB3) with the use of Ni-zeolite/carbon black modified glassy carbon electrode (NiZCB-GCE) is presented. Through the combination of specific properties of the zeolite and carbon black, the proposed sensor showed an enhancement effect on reduction signals of studied vitamins. The NiZCB-GCE exhibited linear response in the range of 0.008–0.24 mg L−1, 0.004–0.22 mg L−1, 0.003–0.1 mg L−1, and 0.15–10 mg L−1 with the limit of detection equal to 2.3 μg L−1, 1.3 μg L−1, 0.92 μg L−1, and 0.045 mg L−1 obtained for VB2, VB9, VB12, and VB3, respectively. The developed protocol was successfully applied for the direct determination of the above-mentioned vitamins in dietary supplements, multivitamin juices and energy drinks, and food products, i.e., breakfast cereals and instant cocoa drinks without laborious sample preparation.