浩瀚污染源废气中的非甲烷总烃测定总烃柱和甲烷柱GDX-104

非甲烷总烃(NMHC)指除甲烷以外挥发性碳氢化合物(其中主要是C2—C8)的总合,长期以来一直是环境空气监测的一项重要指标,我国《大气污染物综合排放标准》GB16927—1996规定非甲烷总烃的厂界浓度标准为4 mg·m-3,《固定污染源排气中非甲烷总烃的测定气相色谱法》HJ/T 38—1999描述了具体的检测方法。

浩瀚色谱（山东）应用技术开发有限公司以HJ/T 38-1999为基础,针对气相色谱法测定污染源废气中非甲烷总烃存在的诸多问题进行探讨,在总烃出峰峰形、废气氧峰值测定、高沸点物质干扰等方面做了研究试验。结果表明,1ml定量环容易造成总烃出现平头峰,改成0.25ml定量环能得到好的峰形;非甲烷总烃的检出限为0.04 mg/m~3(以碳计);氧峰值与氧量具有线性关系,应根据氧量判断氧峰值大小,而不是统一扣除除烃空气氧峰值;废气中存在高沸点组分时,容易吸附于采样容器内壁,将样品加热至100℃再测试可提高该组分的检出率。
 

甲烷柱：长3m，内径（外径）3mm，英制1/8的不锈钢柱，填充GDX-104多孔微球载体60-80目。

总烃柱：装硅烷化玻璃微珠或不装任何填料（空柱），长1m，内径（外径）3mm，英制1/8的不锈钢柱。

应用：HJ/T 38-1999 固定污染源排气中非甲烷总烃的测定 气相色谱法

Non-methane total hydrocarbons (NMHC) refers to the sum of volatile hydrocarbons (mainly C2-C8) other than methane. It has long been an important indicator of ambient air monitoring. my country's "Comprehensive Emission Standard of Air Pollutants" GB16927-1996 stipulates that the plant boundary concentration standard of non-methane total hydrocarbons is 4 mg·m-3, and "Determination of Non-methane Total Hydrocarbons in Exhaust from Stationary Pollution Sources by Gas Chromatography" HJ/T 38-1999 describes specific detection methods.

On the basis of HJ/T 38-1999, Haohan Chromatography (Shandong) Applied Technology Development Co., Ltd. discusses the many problems in the determination of non-methane total hydrocarbons in the exhaust gas of pollution sources by gas chromatography. Research and experiments have been done in the areas of determination and interference of high boiling point substances. The results show that 1ml quantitative loop is likely to cause flat peaks in total hydrocarbons, and changing to 0.25ml quantitative loop can get a good peak shape; the detection limit of non-methane total hydrocarbons is 0.04 mg/m~3 (calculated by carbon); oxygen peak It has a linear relationship with the amount of oxygen. The peak value of oxygen should be judged based on the amount of oxygen, rather than uniformly deducting the peak of oxygen in the air except for hydrocarbons; when there are high boiling point components in the exhaust gas, it is easy to adsorb on the inner wall of the sampling container, and the sample is heated to 100°C before testing The detection rate of this component can be improved.

Methane column: 3m long, 3mm inner diameter (outer diameter), stainless steel column of 1/8 inch, filled with GDX-104 porous microsphere carrier 60-80 mesh.

Total hydrocarbon column: a stainless steel column with silanized glass beads or no packing (empty column), length 1m, inner diameter (outer diameter) 3mm, 1/8 inch.

Application: HJ/T 38-1999 Determination of non-methane total hydrocarbons in exhaust gas from stationary sources-Gas chromatography