Method for analyzing iminodiacetic acid component in N-(phosphonomethyl) aminodiacetic acid (PMIDA) mother liquor

Abstract

The invention relates to a method for analyzing component of N-(phosphonomethyl) aminodiacetic acid (PMIDA) mother liquor, in particular to a component analysis method in which iminodiacetonitrile is used as a main raw material for producing the PMIDA. The method can be used for measuring phosphoric acid, nitrilotriacetic acid and the PMIDA which release inert hydrogen quantitatively by virtue of the separated measurement on the content of the PMIDA, nitrilotriacetic acid and iminodiacetic acid in the mother liquor and the measurement on polybasic acids such as the PMIDA, the phosphoric acid and phosphorous acid step by step and simultaneously by adopting calcium chloride to strengthen weak acid; and the content of iminodiacetic acid, the PMIDA, nitrilotriacetic acid, phosphorous acid, hydrochloric acid and phosphoric acid in the PMIDA mother liquor can be skillfully measured according to the reaction law and interrelation of all substances. The method is proven to be accurate, comprehensive, scientific, reasonable and simple in operation, and provides a reliable basis for recycling and comprehensively utilizing the PMIDA mother liquor, thus having good popularization value.

Description

[0001] The present invention is a divisional application of the invention patent application with the patent application number 201010552827.5, the application date is November 22, 2010, and the title is "A Method for Analyzing Diglyphosate Mother Liquor Components". technical field [0002] The invention relates to a method for analyzing the components of diglyphosate mother liquor, in particular to a method for analyzing the components of mother liquor produced when diglyphosate is produced by using iminodiacetonitrile as the main raw material, and belongs to the field of chemical analysis. Background technique [0003] Diglyphosate (N-(phosphomethyl)iminodiacetic acid) It is an intermediate for the production of glyphosate (N-phosphonomethylglycine) from iminodiacetonitrile (IDA method). Glyphosate is a widely used organic phosphine herbicide, which has the characteristics of high efficiency, broad spectrum, low toxicity and safety, and is very effective in the control o...

AI Technical Summary

Problems solved by technology

However, it is very difficult to deal with diglyphosate mother liquor in production at present, the main reason is that the composition of the mother liquor is relatively complex, and there are no relevant reports on the comprehensive analysis of diglyphosate mother liquor, and the actual analysis of many components of diglyphosate mother liquor has not yet established analytical methods

At present, the determination of the iminodiacetic acid content of a single component in the solution mainly adopts the acid-base titration method using methyl red as an indicator; the determination of the content of phosphorous acid, phosphoric acid and hydrochloric acid of a single component in the solution mainly adopts conventional methods. Acid-base titration, directly titrate with alkali standard solution; for the determination of the content of diglyphosate in the solution, mainly use lead nitrate standard solution for complexometric titration, with pH 9.0 buffer solution and arsenazo as indicators Mainly adopt sodium sulfite addition method etc. to the mensuration of formaldehyde content in the solution; To the mensuration of the nitrilotriacetic acid of single component, in the prior art, use nitrogen determination method to measure nitrilotriacetic acid content, but nitrogen-containing compound is more in the mother liquor, interferes Large, there is also an acid-base complexometric titration method, that is, after dissolving nitrilotriacetic acid with alkali, adjust it with acid-base until methyl red just turns yellow, add zinc nitrate solution to form a complex to precipitate acid, and titrate with alkali standard solution. There are also chromazurin S-hexadecyltrimethylammonium bromide as an indicator, titrated with copper nitrate standard solution at pH = 6, but the composition of diglyphosate is complex, and the nitrilotriacetic acid and bisphosphonate contained in the mother liquor Glyphosate has complexation property, which interferes with complexometric titration, and nitrilotriacetic acid is also acidic, and is a polyacid, which, like other acidic substances in the mother liquor, can react with alkali, so the determination of nitrilotriacetic acid is carried out by the above chemical analysis method. The content of acetic acid will be interfered by other substances in the mother liquor, making the measurement results inaccurate

Mo Qingkui's "Content Determination of Hydrochloric Acid and Phosphorous Acid in the Recovery Solution of Diglyphosate Production" is used to determine the content of hydrochloric acid and phosphorous acid in the distilled liquid of the synthesis reaction of diglyphosate. The distilled liquid has simple components, mainly containing hydrochloric acid, Phosphorous acid and formaldehyde, while the composition of the mother liquor is complex, the properties of several components have similarities, the analysis is difficult, and there is no relevant literature report

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