固定相：高聚物
規(guī)格2m*3mm，2m*4mm，2m*1/8
粒度：60-80目
型號(hào)：GDX-104，GDX-502

固定相：硅烷化玻璃微球

應(yīng)用：HJ 38-2017 固定污染源廢氣 總烴、甲烷和非甲烷總烴的測(cè)定 氣相色譜法（發(fā)布稿）

非甲烷總烴通常是指除甲烷以外的所有可揮發(fā)的碳?xì)浠衔?當(dāng)空氣中的非甲烷總烴含量超標(biāo)時(shí),不僅會(huì)造成光化學(xué)煙霧造成環(huán)境污染,同時(shí)還會(huì)對(duì)人體健康造成較大威脅,所以,在開(kāi)展環(huán)境監(jiān)測(cè)工作時(shí),必須科學(xué)、準(zhǔn)確測(cè)定大氣中的非甲烷總烴。但是,當(dāng)前所用測(cè)定方法存在較多不足之處,容易出現(xiàn)總烴峰型異常現(xiàn)象,所以,便需要通過(guò)改進(jìn)測(cè)定方法,確保測(cè)定結(jié)果的性。

滕州市浩瀚色譜儀器技術(shù)服務(wù)有限公司，用直接進(jìn)樣差量氣相色譜法測(cè)定非甲烷總烴(NMHC)量。實(shí)驗(yàn)研究了分析條件、氣源和定量方式等對(duì)NMHC定量準(zhǔn)確度的影響。綜合考慮較低基線響應(yīng)和較高靈敏度等,選擇合適的氫氣和空氣流速,測(cè)得NMHC方法檢出限為0.03 mg/m3(以碳計(jì)),該法可低濃度樣品分析的準(zhǔn)確度。實(shí)驗(yàn)結(jié)果表明,標(biāo)準(zhǔn)氣中CH4和C3H8遵從碳數(shù)響應(yīng)規(guī)律,其配比不會(huì)影響定量的準(zhǔn)確性,可根據(jù)樣品總烴和甲烷比例適當(dāng)配制;對(duì)于低濃度樣品,以空氣為底氣的總烴響應(yīng)靈敏度低于氮?dú)鉃榈讱獾目偀N響應(yīng)靈敏度,采用以氮?dú)鉃榈讱獾臉?biāo)準(zhǔn)氣來(lái)定量空氣中總烴的含量時(shí),測(cè)定結(jié)果將產(chǎn)生較大偏差,甚可能產(chǎn)生負(fù)值,應(yīng)該用以除烴空氣為底氣的標(biāo)準(zhǔn)氣來(lái)定量空氣樣品;某些樣品測(cè)定過(guò)程中,總烴不只出一個(gè)峰,需要調(diào)節(jié)相關(guān)條件再進(jìn)行測(cè)定。

GDX502甲烷柱測(cè)定大氣中非甲烷總烴 圖片：


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