1.1 本标准是一种测试方法，教授如何使用放射性碳分析实验测量固体、液体和气体样品中的生物基碳含量。这些测试方法不涉及环境影响、产品性能和功能、地理来源的确定或遵守联邦法律所需的生物基碳量的分配。 1.2 这些试验方法适用于任何含有碳基成分的产品，这些成分可以在氧气存在下燃烧产生二氧化碳（CO 2. 气体总体分析方法也适用于气体样品，包括公用事业锅炉和废物焚烧炉的烟气。 1.3 尽管参考资料部分参考了仪器选择的最低要求，但这些测试方法并未试图教授所用仪器的基本原理。但是，对上述试验方法的样品制备进行了说明。此处不包括仪器操作的详细信息。这些最好从所用特定仪器的制造商处获得。 1.4 限制 本标准适用于不接触人造碳-14的实验室( 14 C人造的 14 液体闪烁计数器（LSC）和加速器质谱（AMS）实验室在生物医学研究中经常使用C，并且在实验室内的水平可以是1000倍或100倍以上 % 生物基材料和100000倍以上1%的生物基材料。一旦进入实验室，人工 14 C可能会在门把手、笔、桌面和其他表面上变得无处不在，但它可能会随机污染未知样本，产生不准确的高生物基结果。 尽管大力尝试清理人工污染 14 C从实验室中，隔离已被证明是唯一成功的避免方法。暴露在人工环境中的实验室需要完全独立的化学实验室和极端的检测验证措施 14 C.接受的要求是: 1. 向客户披露，处理其产品和材料的实验室也使用人工 14 C 2. 独立建筑中的化学实验室，用于处理人工 14 C和生物样品 3. 不进入另一方建筑的单独人员 4. 不共享午餐室和办公室等公共区域 5. 两者之间不共享物资或化学品 6. 检测器内的准同时质量保证测量验证检测器本身内不存在污染。 ( 1. , 2. 和 3. ) 2. 1.5 本标准并不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。 注1: ISO 16620-2等同于本标准。 1.6 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====== 4.1 该测试方法为碳源与CO直接平衡的材料提供了准确的生物基/生物碳含量结果 2. 在呼吸或新陈代谢停止时在大气中，例如在田地里收割过自然生活的作物或草。将测试方法应用于人工环境中产生的材料需要特别考虑。这些测试方法在CO衍生材料中的应用 2. 人工环境中的吸收超出了本标准的当前范围。 4.2 方法B利用AMS和同位素比质谱（IRMS）技术来量化给定产品的生物基含量。 仪器误差可在0.1-0.5%（1个相对标准偏差（RSD））内，但对照研究确定实验室间总不确定度高达±3 % 完全的该误差不包括生物基内容来源的不确定误差来源（见第22节关于精度和偏差）。 4.3 方法C使用LSC技术，使用已转化为苯的样品碳来量化产品的生物基含量。该测试方法测定样品的生物基含量，最大总误差为±3 % （绝对），方法B也是如此。 4.4 这里描述的测试方法直接区分了当代碳输入产生的产品碳和化石输入产生的碳。产品的测量 14 C 12 C或 14 C 13 C含量是相对于放射性碳测年界所接受的碳基现代参考材料如NIST标准参考材料（SRM）4990C（称为OXII或HOxII）来测定的。它在组成上与原始草酸放射性碳标准SRM 4990B（称为OXI或HOxI）直接相关，并用f表示 M ，即样品在现代碳中的比例。（参见术语，第节 3. .) 4.5 必须正确使用所有实施这些测试方法的实验室可用的参考标准，以建立初级碳同位素标准的可追溯性，并且所述的不确定性是有效的。主要标准为SRM 4990C（草酸） 14 C和RM 8544（NBS 19方解石） 13 C.这些材料可从美国国家标准与技术研究所（NIST）在北美分销，也可从奥地利维也纳国际原子能机构（IAEA）在北美以外分销。 4.6 这些试验方法的可接受国际单位制偏差（公差）为±5 % 除非另有说明。

1.1 This standard is a test method that teaches how to experimentally measure biobased carbon content of solids, liquids, and gaseous samples using radiocarbon analysis. These test methods do not address environmental impact, product performance and functionality, determination of geographical origin, or assignment of required amounts of biobased carbon necessary for compliance with federal laws. 1.2 These test methods are applicable to any product containing carbon-based components that can be combusted in the presence of oxygen to produce carbon dioxide (CO 2 ) gas. The overall analytical method is also applicable to gaseous samples, including flue gases from electrical utility boilers and waste incinerators. 1.3 These test methods make no attempt to teach the basic principles of the instrumentation used although minimum requirements for instrument selection are referenced in the References section. However, the preparation of samples for the above test methods is described. No details of instrument operation are included here. These are best obtained from the manufacturer of the specific instrument in use. 1.4 Limitation— This standard is applicable to laboratories working without exposure to artificial carbon-14 ( 14 C). Artificial 14 C is routinely used in biomedical studies by both liquid scintillation counter (LSC) and accelerator mass spectrometry (AMS) laboratories and can exist within the laboratory at levels 1,000 times or more than 100 % biobased materials and 100,000 times more than 1% biobased materials. Once in the laboratory, artificial 14 C can become undetectably ubiquitous on door knobs, pens, desk tops, and other surfaces but which may randomly contaminate an unknown sample producing inaccurately high biobased results. Despite vigorous attempts to clean up contaminating artificial 14 C from a laboratory, isolation has proven to be the only successful method of avoidance. Completely separate chemical laboratories and extreme measures for detection validation are required from laboratories exposed to artificial 14 C. Accepted requirements are: (1) disclosure to clients that the laboratory(s) working with their products and materials also works with artificial 14 C (2) chemical laboratories in separate buildings for the handling of artificial 14 C and biobased samples (3) separate personnel who do not enter the buildings of the other (4) no sharing of common areas such as lunch rooms and offices (5) no sharing of supplies or chemicals between the two (6) quasi-simultaneous quality assurance measurements within the detector validating the absence of contamination within the detector itself. ( 1 , 2 , and 3 ) 2 1.5 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. Note 1: ISO 16620-2 is equivalent to this standard. 1.6 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 ====== 4.1 This testing method provides accurate biobased/biogenic carbon content results to materials whose carbon source was directly in equilibrium with CO 2 in the atmosphere at the time of cessation of respiration or metabolism, such as the harvesting of a crop or grass living its natural life in a field. Special considerations are needed to apply the testing method to materials originating from within artificial environments. Application of these testing methods to materials derived from CO 2 uptake within artificial environments is beyond the present scope of this standard. 4.2 Method B utilizes AMS along with Isotope Ratio Mass Spectrometry (IRMS) techniques to quantify the biobased content of a given product. Instrumental error can be within 0.1-0.5 % (1 relative standard deviation (RSD)), but controlled studies identify an inter-laboratory total uncertainty up to ±3 % (absolute). This error is exclusive of indeterminate sources of error in the origin of the biobased content (see Section 22 on precision and bias). 4.3 Method C uses LSC techniques to quantify the biobased content of a product using sample carbon that has been converted to benzene. This test method determines the biobased content of a sample with a maximum total error of ±3 % (absolute), as does Method B. 4.4 The test methods described here directly discriminate between product carbon resulting from contemporary carbon input and that derived from fossil-based input. A measurement of a product’s 14 C/ 12 C or 14 C/ 13 C content is determined relative to a carbon based modern reference material accepted by the radiocarbon dating community such as NIST Standard Reference Material (SRM) 4990C, (referred to as OXII or HOxII). It is compositionally related directly to the original oxalic acid radiocarbon standard SRM 4990B (referred to as OXI or HOxI), and is denoted in terms of f M , that is, the sample’s fraction of modern carbon. (See Terminology, Section 3 .) 4.5 Reference standards, available to all laboratories practicing these test methods, must be used properly in order that traceability to the primary carbon isotope standards are established, and that stated uncertainties are valid. The primary standards are SRM 4990C (oxalic acid) for 14 C and RM 8544 (NBS 19 calcite) for 13 C. These materials are available for distribution in North America from the National Institute of Standards and Technology (NIST), and outside North America from the International Atomic Energy Agency (IAEA), Vienna, Austria. 4.6 Acceptable SI unit deviations (tolerance) for the practice of these test methods is ±5 % from the stated instructions unless otherwise noted.