Method for determining silicate and phosphate ions with ion chromatography post-column derivatization method

Abstract

The invention discloses a method for determining silicate and phosphate ions with an ion chromatography post-column derivatization method. The method comprises the steps that a water solution of a sample to be determined is diluted to a certain multiple times firstly and then the solution is sampled; after the solution is separated and eluted by an anion exchange chromatography column, the separated and diluted solution is derived by an acidified sodium molybdate solution and reduced by ascorbic acid, a product is strongly absorbed in a near infrared region, so that the silicate and phosphate ions are subjected to separated detection; the concentration and the acidity of a post-column derivatization reagent and a reductant are adjusted before determination, so that a derivative compound has the concentration with maximum absorption value, and further high limit of detection and accuracy can be obtained. According to the method, a conventional anion exchange analytical column is used for separating two ions; compared with other reported separation methods, an ion exchange chromatography has higher separation capability and is usually applied to separating ions with similar properties, and therefore, the ion exchange chromatography can be applied to separating the silicate and phosphate ions in complex matrix systems; the method has high application prospects and values.

Description

technical field [0001] The invention relates to an ion chromatographic post-column derivatization system, in particular to a new method for determining silicate and phosphate by using the post-column derivatization method of ion chromatogram. Background technique [0002] As we all know, silicon and phosphorus play an irreplaceable role in organisms. Silicon is the second most abundant element on earth after oxygen, while phosphorus is the basic element of genetic material nucleic acid. The content of the two elements in the water body has a great influence on the growth of algae plants. Monitoring the content of silicon and phosphorus in the water body has a great role and effect in controlling the eutrophication pollution of the water body [1-2]. [0003] At present, for the two elements, the two elements are mostly used to react with molybdate to form silicon molybdenum yellow and phosphomolybdenum yellow heteropolyacid [3], or further use a reducing agent to reduce to fo...

AI Technical Summary

Problems solved by technology

Because the properties of the two ions are relatively similar when forming heteropolyacids, it is very challenging to develop simultaneous determination of two ions

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