1.1 此测试方法 2. 介绍了环境、室内或工作场所大气中非甲烷有机化合物（NMOC）的取样和测定程序。 1.2 本试验方法描述了在硅烷化或其他钝化不锈钢罐中收集完整的全空气样本，以及随后的实验室分析。 1.2.1 本试验方法描述了在高于大气压力的最终压力下在罐中取样的程序（加压取样）。 1.3 该测试方法采用低温捕获程序，在分析之前对NMOC进行浓缩。 1.4 本试验方法描述了在不使用气相色谱柱和物种分离所需的其他程序的情况下，通过火焰离子化检测（FID）测定NMOC。 1.5 此测试方法的范围为20 ppb C至10 000 ppb丙 ( 1. , 2. ) . 3. 1.6 与简单碳氢化合物或芳香族化合物相比，该测试方法对某些卤化或含氧碳氢化合物的不确定度更大。如果存在高浓度的氯烃或氯氟烃，情况尤其如此。 1.7 以国际单位制表示的数值应视为标准。括号中给出的值是英寸磅单位的数学转换，仅供参考，不被视为标准。 1.8 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的使用者有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1.9 本国际标准是根据世界贸易组织技术性贸易壁垒委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认的标准化原则制定的。 ====意义和用途====== 5.1 许多监管机构、工业过程和其他利益相关者要求确定大气中的NMOC。 5.2 准确测量环境NMOC浓度对于制定空气污染控制策略和评估控制效果至关重要，因为NMOC是大气臭氧和其他氧化剂的主要前体 ( 7. , 8. ) . 5.2.1 通常在城市地点发现的NMOC浓度范围可达1 ppm C至3 ppm C或更高。为了确定前体进入区域监测站点的运输，可能需要测量站点逆风处的NMOC。来自无NMOC来源地区的农村NMOC浓度可能低于1的十分之几 ppm C。 5.3 基于气相色谱法以及定性和定量物种评估的传统测试方法相对耗时，有时在人员时间和资源方面困难且昂贵，并且当只需要测量NMOC时不需要。所描述的测试方法只需要简单的低温预处理- 浓缩程序，然后用FID直接检测。在不需要特定数据的情况下，该测试方法可对环境总NMOC浓度进行灵敏准确的测量。本标准试验方法的典型用途如下。 5.4 试验方法的一个应用是监测罐的清洁度。 5.5 测试方法的另一个用途是在分析之前对罐样品进行筛选。 5.6 在加压罐中收集环境空气样本具有以下优点: 5.6.1 在特定时间段内方便地收集集成的环境样本， 5.6.2 具有远程采样和后续中央实验室分析的能力， 5.6.3 如有必要，能够运送和储存样品， 5.6.4 无人值守样本采集， 5.6.5 用一个分析系统分析来自多个地点的样品， 5.6.6 收集重复样品以评估测量精度，以及 5.6.7 特定碳氢化合物分析可以使用相同的样品系统进行。

1.1 This test method 2 presents a procedure for sampling and determination of non-methane organic compounds (NMOC) in ambient, indoor, or workplace atmospheres. 1.2 This test method describes the collection of integrated whole air samples in silanized or other passivated stainless steel canisters, and their subsequent laboratory analysis. 1.2.1 This test method describes a procedure for sampling in canisters at final pressures above atmospheric pressure (pressurized sampling). 1.3 This test method employs a cryogenic trapping procedure for concentration of the NMOC prior to analysis. 1.4 This test method describes the determination of the NMOC by the flame ionization detection (FID), without the use of gas chromatographic columns and other procedures necessary for species separation. 1.5 The range of this test method is from 20 ppb C to 10 000 ppb C ( 1 , 2 ) . 3 1.6 This test method has a larger uncertainty for some halogenated or oxygenated hydrocarbons than for simple hydrocarbons or aromatic compounds. This is especially true if there are high concentrations of chlorocarbons or chlorofluorocarbons present. 1.7 The values stated in SI units are to be regarded as standard. The values given in parentheses are mathematical conversions to inch-pound units that are provided for information only and are not considered standard. 1.8 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.9 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. ====== Significance And Use ====== 5.1 Many regulators, industrial processes, and other stakeholders require determination of NMOC in atmospheres. 5.2 Accurate measurements of ambient NMOC concentrations are critical in devising air pollution control strategies and in assessing control effectiveness because NMOCs are primary precursors of atmospheric ozone and other oxidants ( 7 , 8 ) . 5.2.1 The NMOC concentrations typically found at urban sites may range up to 1 ppm C to 3 ppm C or higher. In order to determine transport of precursors into an area monitoring site, measurement of NMOC upwind of the site may be necessary. Rural NMOC concentrations originating from areas free from NMOC sources are likely to be less than a few tenths of 1 ppm C. 5.3 Conventional test methods based upon gas chromatography and qualitative and quantitative species evaluation are relatively time consuming, sometimes difficult and expensive in staff time and resources, and are not needed when only a measurement of NMOC is desired. The test method described requires only a simple, cryogenic pre-concentration procedure followed by direct detection with an FID. This test method provides a sensitive and accurate measurement of ambient total NMOC concentrations where speciated data are not required. Typical uses of this standard test method are as follows. 5.4 An application of the test method is the monitoring of the cleanliness of canisters. 5.5 Another use of the test method is the screening of canister samples prior to analysis. 5.6 Collection of ambient air samples in pressurized canisters provides the following advantages: 5.6.1 Convenient collection of integrated ambient samples over a specific time period, 5.6.2 Capability of remote sampling with subsequent central laboratory analysis, 5.6.3 Ability to ship and store samples, if necessary, 5.6.4 Unattended sample collection, 5.6.5 Analysis of samples from multiple sites with one analytical system, 5.6.6 Collection of replicate samples for assessment of measurement precision, and 5.6.7 Specific hydrocarbon analysis can be performed with the same sample system.