System and method for simultaneously determining content of trivalent chromium and hexavalent chromium through ion chromatography post-column derivation

Abstract

The invention discloses a system and method for simultaneously determining content of trivalent chromium and hexavalent chromium through ion chromatography post-column derivation. The system comprisesa sample flow path, an eluent flow path, a post-column derivation liquid flow path, an analysis flow path, an injection valve, an injection ring, an ultraviolet-visible detector and a computer processing system, wherein the analysis flow path is formed by sequentially connecting a cation exchange chromatographic column, a three-way valve, a braided reaction tube and an optical flow cell in series. According to the method disclosed by the invention, the content of trivalent chromium and hexavalent chromium is simultaneously determined by adopting an IC-UV-Vis method, the method has existing application in water quality detection, trivalent chromium and hexavalent chromium in drinking water can be simultaneously determined by existing researchers by ion chromatography, the detection limit is low, and the method is excellent in reproducibility and sensitivity. Since the trivalent chromium and hexavalent chromium in toy materials need to be leached and tested, the leaching method in EN71-3 is used in the research, the chromatographic conditions are optimized after leaching liquor treatment, and the content of the trivalent chromium and hexavalent chromium in the leaching liquor is tested. The method is high in sensitivity and excellent in repeatability.

Description

technical field [0001] The invention relates to the technical field of content determination of trivalent chromium and hexavalent chromium, and specifically refers to a system and method for simultaneously determining the content of trivalent chromium and hexavalent chromium by ion chromatography-post-column derivatization. Background technique [0002] Due to the particularity of children's toys, especially toys for children younger than three years old, they are frequently in contact with children's bodies and facial features. If the content of heavy metals exceeds the standard, long-term exposure will cause harm to children. Hexavalent chromium is easily absorbed by the human body. It can invade the human body through digestion, respiratory tract, skin and mucous membranes. Ingestion may cause cancer and has a long-lasting danger to the environment. Toy product regulations in various regions have strict limit requirements for hexavalent chromium. Although the toxicity of...

AI Technical Summary

Problems solved by technology

At present, the test methods recommended by the new regulations are ICP-AES method and LC-ICP-MS method. The ICP-AES method can meet the test requirements of most elements in the regulations, but the ICP-AES method cannot distinguish and test the trivalent of different valence states. The migration amount of chromium and hexavalent chromium, and the limit value of hexavalent chromium is low, and the detection limit of ICP-AES method cannot meet the requirements

The LC-ICP-MS method can separate and test trivalent chromium and hexavalent chromium, and the test accuracy also meets the test requirements, but the equipment cost is relatively expensive, and the penetration rate in the laboratory is low, and the test method is not conducive to popularization

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