This standard specifies the gas-liquid chromatography method for the average relative molecular mass of fatty alkyl dimethyl betaine by packed column. This standard is applicable to the determination of a single type of sample, not to mixtures with other components or samples containing other interfering organic compounds. QB/T 2345-1997 Gas-liquid chromatography method for the determination of the average relative molecular mass of fatty alkyl dimethyl betaine QB/T2345-1997 Standard download decompression password: www.bzxz.net

【Classification number】Y43
Preparation number: 996--1998
Light Industry Standard of the People's Republic of China
QB/T 2345---97
Fatty alkyl dimethyl betaine
Determination of average relative molecular masswww.bzxz.net
Gas-liquid chromatography
Published on 1998-01-16
Published by China Light Industry General Association
Implementation on 1998-09-01
This standard was proposed by the Quality Standards Department of China Light Industry General Association and issued by the National Surfactant Detergent Standardization Center: This standard was drafted by China Daily Chemical Industry Research Institute. The main drafters of this standard are: Zhou Luanbao Fanhu. rKAoNrKAca
1 Specification
Light Industry Standard of the People's Republic of China
Determination of average relative molecular mass of fatty alkyl dimethyl betaine
Gas-liquid chromatography
QB/T2345-87
This standard specifies the packed column gas-liquid chromatography method for determining the average relative molecular mass of fatty alkyl dimethyl betaine. This standard is applicable to the determination of a single type of sample, not to mixtures with other components and samples containing other interfering organic compounds.
2 Principle
The sample is thermally decomposed in the gas chromatograph chamber, and the homologous distribution of the thermal decomposition products is used to determine the average molecular mass of fatty alkyl dimethyl amine.
The average relative molecular mass of fatty alkyl dimethyl betaine is calculated by adding the average relative molecular mass of fatty alkyl dimethyl amine to the mass of CH and COO.
3 Reagents and reference samples
Analytical reagents and water of equivalent purity should be used in the analysis. 3.1 Reference sample Fatty alkyl dimethylamine of known chain length, such as C1-fatty alkyl dimethylamine. A product of known composition can be used as a reference sample to check the performance of the chromatograph. 3.2 Carrier gas high-purity nitrogen.
4 Apparatus
4.1 The chromatograph has a flame ionization detector and a program upgrade device. 4.2 Column: The column tube is made of a cyclic material (e.g. glass or stainless steel with an inner diameter of 2~~Ami and a length of 0.5~1.5m; the carrier is Chrom050rbWAWDMCS or 405 silanized white carrier with a particle size of 150~180μm, coated with 5%~10% potassium oxide and 5%~10% Apizon grease L (Apizon L). Pre-aging is required before the test, and the chromatographic peaks of fatty alkyl dimethylamines with different carbon chains must be well separated. 4.3 The vaporization chamber is filled with a silanized glass microbead carrier (150~180μm). 4.4 Electronic integrator.
4,5 Recorder.
4.6 Syringe 5 or 10μL.
Approved by China Light Industry General Association on January 16, 1993
Implemented on September 1, 1993
5 Test Procedure
5.1 Sample| |tt||QB/T2345--97
Take about 0.5% of the sample and add a little water to dissolve it: so that the sample can be sucked with a syringe (46). 5.2 Chromatographic analysis
5.2.1 Setting of chromatographic analysis conditions
) The temperature of the vaporization chamber is greater than 300°C:
b) The column temperature is programmed to rise, with the initial temperature at 110~130°C, constant temperature for 2min, and the temperature rises to the final temperature at 270~290°C at a rate of 3~5°C/min, and the rise time is 8~9min; c) The carrier gas flow rate is 30~50mL/min;
d) The detector temperature is greater than: 100°C.
5.2.2 Instrument performance test
Inject a certain amount of reference sample (3, 1) into the chromatograph so that the chromatographic peaks of each carbon chain fatty alkyl dimethylamine can be well separated, and record the retention time for comparison with the test sample. 5.2.3 Sample test
Introduction of sample: Use a syringe (4.6) to inject a sufficient amount of sample (5.1) into the chromatograph so that the peak height of the obtained chromatogram is appropriate.
A typical chromatogram is shown in Figure 1.
Testing of free chromatograms
6.1 Qualitative analysis
Identify the components of the sample by comparing the sample chromatogram with the reference sample chromatogram (5.2, 2). 6.2 Quantitative analysis
Use an electronic integrator (4.4) to determine the peak area of ​​each carbon chain fatty alkyl monomethylamine and calculate the total peak area. The results are as follows: 1. Calculation: 1) The percentage of the peak area (αi) of the carbon-chain fatty alkyl dimethylamine to the total peak area (A) of the fatty alkyl dimethylamine (B) is calculated according to formula (1):
Bi-×100
b) The average relative molecular mass (Mt) of the fatty alkyl dimethylamine is calculated according to formula (2): M
2) The average relative molecular mass (MB) of the fatty alkyl dimethylamine is calculated according to formula (3): Ma=Mt+58.0
The percentage of the peak area of ​​the carbon-chain fatty dimethylamine to the total peak area of ​​the fatty alkyl dimethylamine; In the formula. Bi-
TKAONTKAca
QE/T2345-$7
The peak area of ​​ii carbon chain fatty alkyl dimethylamine: A-The total peak area of ​​fatty alkyl dimethylamine: M;--The theoretical relative molecular mass of i carbon chain fatty alkyl dimethylamine, see Table 1: Mt--The average relative molecular mass of fatty alkyl dimethylamine; MB--The average relative molecular mass of fatty alkyl dimethyl betaine: 38.0---The difference between the average relative molecular mass of fatty alkyl dimethylamine and fatty alkyl dimethyl betaine
Theoretical relative molecular mass of each carbon chain fatty alkyl dimethylamine Fatty alkyl carbon number
[157.3171.8/185.3199.4/213.4|227.4|241.5255.5269.6283.5 1297.6|311.8, 325,67.2 Precision
For the same fatty alkyl dimethyl betaine sample, the difference between the parallel determination results of the average relative molecular mass should not exceed 1. Glo
QB/T2345-97
Figure Pyrolysis gas chromatogram of alkyl dimethyl betaineKAoNTKAca
People's Republic of China
Light Industry Bank Substandard Beach
Fat alkyl dimethyl betaine
Determination of average relative molecular mass
Gas-liquid chromatography
QB/T2345-97
China Published by China Light Industry Press
Edited by the Industrial Standard Promotion and Reduction Publishing CommitteeAddress: No. 12, Beihua Road, Chaowai, Beijing
Code: 100020
Tel: [010) 650600222309
No reproduction allowed
All rights reserved
Book number: 1550102391
Price: 4.00 yuan
Print run! 200 copies
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.