基于3D打印薄层池和流场形电极的镉离子流动检测系统

首次提出了流场形(FFS)电极的概念,并印制了FFS三电极体系.结合3D打印的薄层流通池(TLFC),采用方波溶出伏安法(SWSV),构建了镉离子(Cd2+)流动电化学检测系统.考察了电极形状、测量方式、流速、介质条件、富集时间等条件的影响.结果表明,此检测系统测量灵敏度高,重现性和稳定性好.在优化条件下,Cd2+浓度在2 ～ 100 μg/L范围内与溶出峰电流呈良好的线性关系,相关系数为0.997,检出限为0.5 μg/L.将本方法应用于环境水样和生物甲烷发酵液中痕量Cd2+的检测,结果与ICP-AES无显著性差异,加标回收率为90％ ～ 106％.

A flow System for Detection of Cadmium Based on 3D-Printed Thin-layer Cell and Flow-field Shaped Electrode

The concept of flow-field shaped (FFS) electrode was introduced for the first time and a FFS based three-electrodes system was built accordingly. Combined with a 3D-printed thin-layer flow cell (TLFC), a flow electrochemical system for detection of Cd²⁺ using square wave stripping voltammetry (SWSV) was thus constructed. Several factors that might affect the determination of Cd²⁺ were investigated, including the shape of the FFS electrode, the method of measurements, the buffer medium, the flow rate, and the deposition time. The results suggested this new detection system offered high sensitivity, good reproducibility, and great stability. Under the optimized conditions, the system showed a good linearity for detecting Cd²⁺ in the range of 2–100 μg L^?1 with a correlation coefficient of 0.997, and a detection limit of 0.5 μg L^?1 was achieved. Furthermore, the newly designed system was used to determine trace Cd²⁺ in environmental water samples and fermentation broths of biological methane. The results were consistent with that obtained with ICP-AES analysis and the recovery rates were found to be 90%–106%.