Detection method of diaminotoluene isomers

Abstract

The invention discloses a detection method of a diaminotoluene (TDA) isomer. The diaminotoluene isomer is determined by adopting a gas chromatographic method. The detection method comprises the following operation steps: (1), obtaining a to-be-detected diaminotoluene isomer test product; and (2), injecting the test product in a gas chromatograph, wherein chromatographic conditions are as follows: a chromatographic column is a polyethylene glycol (PEG) gas-phase capillary-column chromatographic column, a carrier gas is N2, and the starting column pressure is 0.1MPa, column temperature conditions are as follows: the initial temperature is 130 DEG C, and is kept for 5min, the temperature rise rate is 10 DEG C / min, the final temperature is 200 DEG C and is kept for 20min, the temperature of a vaporizing chamber is 250-280 DEG C, an adopted detector is a flame ionization detector (FID), and the detection temperature is 250-280 DEG C. The detection method disclosed by the invention relates to purities of six isomer monomers of TDA and content analysis of all components of a mixture of the six isomer monomers of the TDA, and the minimum detectable quantity reaches 0.001 percent; meanwhile, six isomers of the TDA can be effectively separated and detected, and thus a TDA production device can continuously and stably run for a long time.

Description

technical field [0001] The invention relates to a method for detecting isomers, in particular to a method for detecting diaminotoluene isomers. Background technique [0002] Diaminotoluene, referred to as TDA, is currently used to detect its isomers by gas chromatography. There is only one main peak in the detection, and the six isomers of TDA cannot be completely separated. For 80 / 20TDA and 20 / 80TDA The isomer ratio cannot be detected, that is to say, 2,6-TDA and 2,4-TDA cannot be completely separated, only the total mass fraction can be detected, and the isomer ratio cannot be calculated, and the isomer ratio cannot be accurately detected. Whether the composition ratio meets the process control and customer requirements. At the same time, for a single product 2,6-TDA or 2,4-TDA, because the two cannot be separated, then our analysis result can only be the sum of the two, and the mass fraction of each component cannot be detected, then our analysis result is not Does not ...

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Problems solved by technology

[0002] Diaminotoluene, referred to as TDA, is currently used to detect its isomers by gas chromatography. There is only one main peak in the detection, and the six isomers of TDA cannot be completely separated. For 80 / 20TDA and 20 / 80TDA The isomer ratio cannot be detected, that is to say, 2,6-TDA and 2,4-TDA cannot be completely separated, only the total mass fraction can be detected, and the isomer ratio cannot be calculated, and the isomer ratio cannot be accurately detected. Whether the composition ratio meets the requirements of process control and customers

At the same time, for a single product 2,6-TDA or 2,4-TDA, because the two cannot be separated, then our analysis result can only be the sum of the two, and the mass fraction of each component cannot be detected, then our analysis result is not Does not represent the true quality of the product

The previous analytical method can only detect the total amount of 2,6-TDA and 2,4-TDA, and cannot separate 2,3-TDA from 3,4-TDA, which cannot meet the detection and separation requirements of high-standard enterprises for products

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