海水重金属自动检测系统研究

基于电化学溶出伏安法研制了一种新型重金属检测系统，实现海水中锌、镉、铅、铜、锰、砷、铁和铬8种重金属元素质量浓度的自动检测。海水经过预处理后，8种重金属元素被分离为3路进入检测系统，锌、镉、铅、铜为一路，锰、砷为一路，铁、铬为一路。系统以银基汞膜电极为电化学传感器，通过PC机多线程控制三路恒电位仪电路、各蠕动泵和电磁阀，实现自动进样、检测和清洗。采用标准加入法进行定量分析，检测下限达到10-6 g/L。每路只需要6 mL样品，一次测量可以在30 min内完成。系统体积小、成本低、可以连续测量，适于现场在线自动监测海水中的重金属浓度分布。

Automatic monitoring system for heavy metals in marine waters

An automatic monitoring system was developed for detecting heavy metal ions in marine waters using electrochemical stripping voltammetry.Simultaneous determination of trace zinc,cadmium,lead,copper,manganese,arsenic,iron and chromium were realized in three pathways after seawater pretreatment.The electrochemical sensors were silver based mercury film electrodes.The system was controlled by PC multithreadingly.Computerized sampling,detection and cleaning were realized automatically by three potentiostat circuits coupled with peristaltic pumps and magnetic valves.Quantitative heavy metals analysis was performed by standard addition method.Detection limit of 10~(-6) g/L was achieved.One measurement can be completed in 30 min with only 6 mL sample of each path.The system is very suitable for on-line and in-situ seawater analysis because of the portability,low cost and capability for fast,automatic and continuous determination of trace heavy metals.