HJ 1042-2019 Ambient air and waste gas—Determination of trimethylamine—Solvent absorption-Headspace/gas chromatography
Professional Standard of the People's Republic of China
HJ 1042-2019
Ambient air and waste gas - Determination of trimethylamine - Solvent absorption-Headspace/gas chromatography
環境空氣和廢氣 三甲胺的測定 溶液吸收-頂空/氣相色譜法
(English Translation)
Issue date: 2019-10-24 Implementation date: 2020-04-24
Issued by the Ministry of Ecology and Environment of the People's Republic of China
1 Scope
This standard specifies the solvent absorption-headspace/gas chromatography for the determination of trimethylamine in ambient air and waste gas emitted from stationary sources.
This standard is applicable to the determination of trimethylamine in ambient air, fugitive emission monitoring point air of stationary sources, and organized emission waste gas.
When a hydrogen flame ionization detector (FID) is used, with an air sampling volume of 20L (reference state) and an absorption solution volume of 10 ml, the method detection limit is 0.004 mg/m3 and the lower limit of determination is 0.016 mg/m3; with a waste gas sampling volume of 20L (standard state) and an absorption solution volume of 50 ml, the method detection limit is 0.04 mg/m3 and the lower limit of determination is 0.16 mg/m3.
When a nitrogen-phosphorus detector (NPD) is used, with an air sampling volume of 20L (reference state) and an absorption solution volume of 10 ml, the method detection limit is 0.0007 mg/m3 and the lower limit of determination is 0.0028 mg/m3; with a waste gas sampling volume of 20L (standard state) and an absorption solution volume of 50 ml, the method detection limit is 0.006 mg/m3 and the lower limit of determination is 0.024 mg/m3.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this standard. For undated references, the latest edition applies.
GB 14554 Emission standards for odor pollutants
GB/T 16157 The determination of particulates and sampling methods of gaseous pollutants emitted from exhaust gas of stationary source
HJ 194 Technical specifications on manual methods for ambient air quality monitoring
HJ 905 Technical specification for environmental monitoring of odor
HJ/T 55 Technical guidelines for fugitive emission monitoring of air pollutants
HJ/T 397 Technical specifications for emission monitoring of stationary source
3 Principle
Trimethylamine in ambient air and waste gas is absorbed by dilute acid; then the absorption solution is transferred to a headspace vial and treated with alkali. At a certain temperature, trimethylamine in the sample volatilizes into the headspace; after the gas-liquid two phases reach thermodynamic dynamic equilibrium, the concentration of trimethylamine in the gas phase is proportional to its concentration in the liquid phase. After separation by gas chromatography, detection is performed using a hydrogen flame ionization detector (FID) / nitrogen-phosphorus detector (NPD). Qualitative analysis is based on the chromatographic peak retention time, and quantitative analysis is based on the external standard method.
Foreword i
1 Scope
2 Normative references
3 Principle
4 Interference and elimination
5 Reagents and materials
6 Instruments and equipment
7 Samples
8 Analytical steps
9 Result calculation and expression
10 Precision and accuracy
11 Quality assurance and control
12 Precautions
13 Waste disposal
