Method for extracting and analyzing trivalent chromium and hexavalent chromium in water sediments

Abstract

The invention belongs to the technical field of heavy metal detection and discloses a method for extracting and analyzing trivalent chromium and hexavalent chromium in water sediments. The method comprises steps of sampling, sample pretreatment, ion exchange state chromium test sample preparation, carbonate combined state chromium test sample preparation, trivalent chromium and hexavalent chromiumdetermination and the like. The method is advantaged in that a pre-column derivatization mode is adopted, Cr(III) and Cr(VI) in the test sample are directly extracted by using EDTA-2Na aqueous solution, complexation reaction of Cr (III) and EDTA-2Na occurs at a certain temperature, then a Hamilton PRP-X100 anion exchange chromatographic column is selected to separate Cr (III) and Cr (VI) baselines, and 52Cr is determined by ICP-MS (Inductively Coupled Plasma Mass Spectrometry), and thereby quantitative analysis of Cr (III) and Cr (VI) in a water sample is realized, pretreatment operation of the sample is simple, convenient and rapid, Cr (III) and Cr (VI) are separated and determined within 6 minutes, requirements of chromium form detection and analysis can be met, and method support is provided for guaranteeing the quality safety of aquatic products and researching a chromium pollution remediation technology.

Description

technical field [0001] The invention relates to the technical field of heavy metal detection, in particular to a method for extracting and analyzing trivalent chromium and hexavalent chromium in water body sediments. Background technique [0002] Chromium widely exists in the atmosphere, water, sediment and organisms. Chromium mainly exists in the form of trivalent chromium Cr(III) and hexavalent chromium Cr(VI), and Cr(II), Cr(IV) and Cr(V) are unstable because they are easily oxidized. It should be noted that the positive significance and toxicity of chromium in the living body have a great relationship with its valence state. The toxicity of metal chromium and Cr(Ⅱ) is very small or even non-toxic; Cr(Ⅲ) plays an important role in maintaining the metabolism of glucose, lipid and protein, and is one of the trace elements necessary for organisms; while Cr(Ⅵ) is An element with toxic effects on biological systems, 100-1000 times more toxic than Cr(Ⅲ). In recent years, wit...

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Problems solved by technology

However, it should be noted that the pollution caused by Cr is difficult to be degraded or reduced. Generally, it can only migrate between different regions or in different environments. During this migration process, due to changes in environmental conditions, Cr will It is inevitable that some changes in form or valence will occur, and the low-concentration chromium will gradually enrich to high-concentration chromium, which will be absorbed by different levels of organisms in the food chain, resulting in different levels of accumulation, thereby restricting the development of aquaculture. development, and cause unpredictable harm to human health

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