Determination of cesium using nickel hexacyanoferrate by stripping voltammetry

The determination of cesium ions (Cs+) is important for various applications, including resource utilization, environmental monitoring, and human health. Electrochemical sensors, with their inherent advantages, stand out as an ideal choice for Cs+ detection. However, electrode materials for Cs+ sensors usually face problems such as poor selectivity and complex synthesis. Herein, a method employing nickel hexacyanoferrate (NiHCF) as the electrode material for stripping voltammetry in the determination of Cs+ was proposed. Both adsorption and electrochemical intercalation exhibited selectivity. In the presence of interfering ions at a 10:1 molar ratio to Cs+, Cs+ were still preferentially intercalated in NiHCF. However, electrochemical intercalation exhibits superior selectivity for Cs+ compared to adsorption. Meanwhile，the effect of adsorption on the detection was minimized by electrochemical intercalation. Based on the standard addition method, Cs+ was determined using both adsorption and electrochemical intercalation methods. The error reduced significantly from 32.7% above the theoretical value through absorption to 9.5% below the theoretical value through electrochemical intercalation. This approach not only enhanced measurement accuracy but also reduced the costs associated with both measurement and preparation. The study proposed a cost-effective and rapid method for Cs+ measurement using Prussian blue analogs.