Simple and Cost-Effective Electrochemical Approach for Monitoring of Vitamin K in Green Vegetables

Abstract

This work presents a simple and sensitive electrochemical sensor for the determination of total vitamin K (K1 and K2) using a disposable screen-printed graphene electrode (SPGE). The application for the determination of vitamin K1 in green vegetables by this sensor was developed. The proposed method is based on controlling of negative potential for seconds and scanning it to a positive for oxidation analysis. The capacitance of SPGE was studied and it showed a higher sensitivity for vitamin K determination in comparison to carbon. The parameters, such as the pH of electrolytes, accumulation potential, accumulation time, etc. were investigated. The limit of detection was observed at 0.099 μg mL−1. This method was successfully applied for the determination of the vitamin K1 in various green vegetables. Therefore, the proposed method can be used for quality control of vitamin K1 in natural samples to create the food composition table. © 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim