产品名称：	GDX502甲烷柱测定大气中非甲烷总烃
产品型号：
品牌：	1941
产品数量：
产品单价：	面议
日期:	2023-07-22

GDX502甲烷柱测定大气中非甲烷总烃的详细资料

GDX502甲烷柱测定大气中非甲烷总烃
GDX502甲烷柱测定大气中非甲烷总烃 详细信息：

固定相：高聚物
规格2m*3mm，2m*4mm，2m*1/8
粒度：60-80目
型号：GDX-104，GDX-502

固定相：硅烷化玻璃微球

应用：HJ 38-2017 固定污染源废气 总烃、甲烷和非甲烷总烃的测定 气相色谱法（发布稿）

非甲烷总烃通常是指除甲烷以外的所有可挥发的碳氢化合物,当空气中的非甲烷总烃含量超标时,不仅会造成光化学烟雾造成环境污染,同时还会对人体健康造成较大威胁,所以,在开展环境监测工作时,必须科学、准确测定大气中的非甲烷总烃。但是,当前所用测定方法存在较多不足之处,容易出现总烃峰型异常现象,所以,便需要通过改进测定方法,确保测定结果的性。

滕州市浩瀚色谱仪器技术服务有限公司，用直接进样差量气相色谱法测定非甲烷总烃(NMHC)量。实验研究了分析条件、气源和定量方式等对NMHC定量准确度的影响。综合考虑较低基线响应和较高灵敏度等,选择合适的氢气和空气流速,测得NMHC方法检出限为0.03 mg/m3(以碳计),该法可低浓度样品分析的准确度。实验结果表明,标准气中CH4和C3H8遵从碳数响应规律,其配比不会影响定量的准确性,可根据样品总烃和甲烷比例适当配制;对于低浓度样品,以空气为底气的总烃响应灵敏度低于氮气为底气的总烃响应灵敏度,采用以氮气为底气的标准气来定量空气中总烃的含量时,测定结果将产生较大偏差,甚可能产生负值,应该用以除烃空气为底气的标准气来定量空气样品;某些样品测定过程中,总烃不只出一个峰,需要调节相关条件再进行测定。

GDX502甲烷柱测定大气中非甲烷总烃 图片：


Determination of non-methane total hydrocarbons in the atmosphere by GDX502 methane column
Determination of non-methane total hydrocarbons in the atmosphere by GDX502 methane column

Stationary phase: high polymer
Specifications 2m*3mm, 2m*4mm, 2m*1/8
Particle size: 60-80 mesh
Model: GDX-104, GDX-502

Stationary phase: silanized glass microspheres
Particle size: 80-60 mesh
Specifications: 2m*4mm, 2m*3mm, 2m*1/8 (Agilent, Shimadzu)
Model: HH-NMHC-2
Application: HJ 38-2017 Determination of total hydrocarbons, methane and non-methane total hydrocarbons from stationary sources - Gas chromatography (release)

Non-methane total hydrocarbons usually refer to all volatile hydrocarbons other than methane. When the non-methane total hydrocarbon content in the air exceeds the standard, it will not only cause environmental pollution caused by photochemical smog, but also pose a great threat to human health. Therefore, in carrying out environmental monitoring work, it is necessary to scientifically and accurately determine the total non-methane hydrocarbons in the atmosphere. However, there are many deficiencies in the currently used measurement methods, and the phenomenon of total hydrocarbon peak type is prone to occur. Therefore, it is necessary to improve the measurement method to ensure the accuracy of the measurement results.

Tengzhou Haohao Chromatography Instrument Technology Service Co., Ltd. used direct injection differential gas chromatography to determine the amount of non-methane total hydrocarbons (NMHC). The effects of analytical conditions, gas source and quantitative methods on the quantitative accuracy of NMHC were studied experimentally. Considering the lower baseline response and higher sensitivity, selecting the appropriate hydrogen and air flow rate, the detection limit of NMHC method is 0.03 mg/m3 (calculated as carbon), which can ensure the accuracy of low concentration sample analysis. The experimental results show that CH4 and C3H8 in the standard gas comply with the carbon number response law, and the ratio does not affect the accuracy of the quantification. It can be properly prepared according to the total hydrocarbon and methane ratio of the sample; for the low concentration sample, the total hydrocarbon with air as the base gas The response sensitivity is lower than the total hydrocarbon response sensitivity of nitrogen as the bottom gas. When the standard gas with nitrogen as the base gas is used to quantify the total hydrocarbon content in the air, the measurement results will have a large deviation, and may even produce a negative value, which should be used to remove hydrocarbons. Air is the standard gas for the bottom gas to quantify the air sample; in some samples, the total hydrocarbons not only have one peak, but the relevant conditions need to be adjusted before measurement.

Determination of non-methane total hydrocarbons in the atmosphere by GDX502 methane column