Gas-phase analytical method for rapid determination of characteristic polymeric materials in mixtures

Abstract

The invention discloses a gas-phase analysis method for quickly measuring characteristic polymer materials in a mixture, which comprises the following steps: firstly, powder the mixture to be measured into a reaction bottle, then add n-octane internal standard solution and adipic acid solution; added hydrogen Put the iodic acid into the above-mentioned reaction bottle and seal it and weigh it; put the reaction bottle in an oven, react fully, take it out and let it cool, weigh again, and take the supernatant as the test sample for analysis; use gas chromatography to analyze the test sample product, start the chromatographic acquisition computer system to collect data; take methyl iodide, ethyl iodide and isopropyl iodide compounds, and transfer them to a stoppered glass vial, add 2ml of n-octane internal standard solution and 2ml of adipic acid The solution was analyzed by gas chromatography at the same time, and then the content of the characteristic polymer in the mixture was calculated. The invention has the advantages of strong specificity, rapid analysis, strong anti-interference and high sensitivity.

Description

technical field [0001] The invention specifically relates to a gas phase analysis method, in particular to a gas phase analysis method for rapidly determining characteristic polymer materials in a mixture. Background technique [0002] In practical work, the qualitative and quantitative analysis of some polymers is difficult, especially the mixture of several polymers is difficult to analyze by conventional methods. For example: some commonly used polymer materials: hypromellose, ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, polyethylene glycol, hydroxyethyl cellulose, Eudragit, etc., are not Ultraviolet response, which cannot be determined by conventional HPLC method with optical detector. [0003] For the above polymer materials, there are often only corresponding pure product quality control methods, and most of them are determined by chemical volumetric method. These methods have poor specificity and low sensitivity, and are only suitable for constan...

AI Technical Summary

Problems solved by technology

[0002] In practical work, the qualitative and quantitative analysis of some polymers is difficult, especially the mixture of several polymers is difficult to analyze by conventional methods

For example: some commonly used polymer materials: hypromellose, ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, polyethylene glycol, hydroxyethyl cellulose, Eudragit, etc., are not UV response, cannot be determined by conventional HPLC method with optical detector

[0003] For the above polymer materials, there are usually only corresponding pure product quality control methods, and most of them are determined by chemical volumetric method. These methods have poor specificity and low sensitivity, and are only suitable for constant analysis of pure products.

For example: the method for determining the content of ethyl cellulose in the Chinese Pharmacopoeia 2005 edition is to first digest the sample, and then use sodium thiosulfate titration, the specificity of this method is poor

In the 2010 edition of the Chinese Pharmacopoeia, there are similar methods for the determination of methoxyl, ethoxyl, and hydroxypropoxyl respectively, but they are only applicable to the detection of pure products and are basically incapable of complex systems.

Images