Site fast detection method for copper, zinc, lead and cadmium as heavy metals in seawater

Abstract

The invention discloses a site fast detection method for copper, zinc, lead and cadmium as heavy metals in seawater, and belongs to the technical field of environment monitoring. A conducting carbon black-ionic liquid paste electrode as a work electrode, Ag / AgCl as a reference electrode and platinum filament or glass carbon as a counter electrode are assembled to form an electrochemical sensor. The concentrations of ionic copper, zinc, lead and cadmium in seawater are respectively determined by adopting square wave anodic stripping voltammetry; and the site fast detection method has the advantages of high sensitivity, favorable repeatability, simple and convenient operation, low expense, quick response, accurate quantification, low requirement on the environment condition and the like, and can be used for site monitoring of offshore pollution and conventional ocean site investigation along with ships.

Description

technical field [0001] The invention belongs to the technical field of environmental monitoring, and in particular relates to an on-site rapid detection method for heavy metals copper, zinc, lead and cadmium in seawater. Background technique [0002] The functions that marine resources can play are severely limited by their environmental quality. Over the last century, pollution from land-based sources has increasingly become a serious threat to effective ocean development. Among them, heavy metal pollution is undoubtedly one of the chief culprits of marine environmental damage, and the ecological, aquatic product quality and safety problems caused by it have repeatedly aroused people's serious attention. UNDP, FAO, WHO and many other international organizations have clearly included it in the list of monitoring objects. The ability to timely and accurately monitor the content of heavy metal elements in seawater is essential for effective assessment and early warning of po...

AI Technical Summary

Problems solved by technology

At present, the generally accepted heavy metal analysis methods include ultraviolet spectrophotometry (UV), atomic absorption method (AAS), atomic fluorescence method (AFS), X-ray fluorescence spectroscopy (XRF), inductively coupled plasma mass spectrometry (ICP-MS), Immunological method (IA), test paper method (TP) and electrochemical method (ES), among which ICP-MS and AAS have better detection limits, and some elements are at PPT level, but the instrument itself is expensive and requires high environmental conditions. The operation is complicated and the cost is high, so now it is mostly used for standard measurement; AFS is mostly used for the analysis and determination of mercury and arsenic in the environment and food, which can be quantified but the operation is cumbersome and the cost is high; UV sensitivity is low and it is not suitable for analysis. Liquid transparency requirements are high, not easy to automate

There is also a common problem in the above methods: it can only be carried out in the laboratory and cannot be used on the test site

However, the pre-coated bismuth film is unstable when exposed to the air and is easily oxidized, resulting in unstable detection signals and poor reproducibility

Co-plating bismuth film method can only be used in acidic medium because bismuth ions are easily hydrolyzed, which limits its application in on-site detection

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