固定污染源排气中非甲烷总烃的测定 气相色谱法
1 适用范围1.1 本标准适用于固定污染源有组织排放和无组织排放的非甲烷总烃（NMHC）测定。 1.2 NMHC的检出限为4×10-2ng。当色谱进样量为1.0ml时，方法的检出浓度为4×10-2mg/m3，方法的定量测定浓度范围为0.12～32mg/m3。
2 定义：非甲烷总烃（NMHC）：指除甲烷以外的碳氢化合物（其中主要是C2~C8）的总称。在本标准规定的条件下所测得的NMHC，是于气相色谱氢火焰离子化检测器有明显响应的、除甲烷外碳氢化合物总量，以碳计。
3 方法原理
用双柱双氢火焰离子化检测器气相色谱仪，注射器直接进样，分别测定样品中的总烃和甲烷总量，以两者之差得非甲烷总烃含量。同时以除烃空气求氧的空白值，以扣除总烃色谱峰中的氧峰干扰。
6 仪器
6.1 气相色谱仪：附氢火焰离子化检测器
6.2 色谱柱
6.2.1 甲烷柱：长3m，内径3mm的不锈钢柱，管内填充GDX-104高分子多孔微球载体60~80目6.2.2 总烃柱：装硅烷化玻璃微珠或不装任何填料（空柱），长1m，内径3mm的不锈钢柱
6.3 色谱柱的填充和老化方法：见附录
B6.4 注射器：全玻璃制1mL、5mL、20mL、50mL、100mL若干个。
6.5 玻璃真空采样瓶：1L
6.6 铝箔复合气体采样袋：3~5L
6.7 采样系统参考GB16157-1996中9.3配置采样装置
6.7.1 采样管用不锈钢、硬质玻璃或氟树脂材质，具有适当尺寸的管料。
6.7.2 流量计装置见GB16157-1996中9.3.6
6.7.3 抽气泵见GB 16157-1996中9.3.7
6.7.4 连接管聚四氟乙烯软管或内衬聚四氟乙烯薄膜的硅橡胶管
6.7.5 无碱玻璃棉
Determination of non methane total hydrocarbons in exhaust gas from fixed pollution sources - Gas chromatography method
1. Scope of Application 1.1 This standard is applicable to the determination of non methane total hydrocarbons (NMHC) in both organized and unorganized emissions from fixed pollution sources. The detection limit of 1.2 NMHC is 4 × 10-2ng. When the chromatographic injection volume is 1.0ml, the detection concentration of the method is 4 × 10-2mg/m3, the quantitative determination concentration range of the method is 0.12-32mg/m3.
2 Definition: Non methane total hydrocarbons (NMHC): Refers to the general term for hydrocarbons (mainly C2-C8) other than methane. The NMHC measured under the conditions specified in this standard is the total amount of hydrocarbons, excluding methane, with a clear response from the gas chromatography hydrogen flame ionization detector, measured in carbon.
3 Method principles
Using a dual column dual hydrogen flame ionization detector gas chromatograph and a syringe for direct injection, determine the total hydrocarbons and total methane in the sample, and calculate the non methane total hydrocarbon content based on the difference between the two. At the same time, calculate the blank value of oxygen using hydrocarbon free air to deduct the interference of oxygen peaks in the total hydrocarbon chromatographic peaks.
6 Instruments
6.1 Gas chromatograph: hydrogen flame ionization detector
6.2 Chromatographic Column
6.2.1 Methane column: a stainless steel column with a length of 3m and an inner diameter of 3mm, filled with GDX-104 polymer porous microsphere carrier of 60-80 mesh. 6.2.2 Total hydrocarbon column: a stainless steel column with a length of 1m and an inner diameter of 3mm, filled with silanized glass microspheres or without any fillers (empty column)
6.3 Filling and aging methods of chromatographic columns: see appendix
B6.4 Syringes: Several all glass 1mL, 5mL, 20mL, 50mL, and 100mL.
6.5 Glass vacuum sampling bottle: 1L
6.6 Aluminum foil composite gas sampling bag: 3~5L
6.7 Sampling System Refer to 9.3 Configuration of Sampling Device in GB16157-1996
6.7.1 The sampling tube shall be made of stainless steel, hard glass, or fluororesin material with appropriate size of tube material.
6.7.2 Flow meter device, see 9.3.6 in GB16157-1996
6.7.3 Air extraction pump, see 9.3.7 in GB 16157-1996
6.7.4 Connecting pipes: PTFE hoses or silicone rubber pipes lined with PTFE film
6.7.5 Alkali free glass wool
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