1.1 该实践涵盖了一种可重复的方法，将硬木、软木、草本材料（如柳枝稷和蚕桑）、农业残留物（如玉米秸秆、小麦秸秆和甘蔗渣）、废纸（如办公垃圾、纸板和新闻纸）、预处理以提高发酵适应性的纤维素原料、谷物、谷物发酵泥、谷物发酵啤酒和发酵残留物转化为适合成分分析的均匀材料。本规程适用于分析前需要干燥的样品。 1.2 碾磨和筛分都会产生大量的灰尘。 这种灰尘可能会造成滋扰和刺激。根据需要使用适当的呼吸保护装置。如果允许过多的灰尘通过空气传播，则可能存在潜在的爆炸危险。根据需要提供适当的防尘措施。 1.3 以国际单位制表示的数值应视为标准。SI单位后括号中给出的值仅供参考，不被视为标准值。 1.4 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。 1.5 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 制备方法A-- 适用于将大量（>20g）现场采集的样品制备成适合成分分析的形式的方法。Woody样品必须首先作为标称5的芯片提供 厘米乘5 cm乘以0。 6. 厘米（2 英寸乘2 in。by 1. / 4. 英寸）或更小，且细枝不超过0.6厘米( 1. / 4. 英寸）直径。草本材料可以加工成整根稻草。建议将废纸切成小于1厘米的碎片( 1. / 2. 英寸）宽。此外，建议细枝、稻草和废纸的长度不应超过61厘米（24英寸），以便于处理。 4.2 制备方法B和C-- 方法适用于非常潮湿的原料、在长时间暴露于环境条件下不稳定的样品，或当房间条件偏离中所述的环境条件时用于干燥材料 3.1.2 这些试验方法也适用于处理小样本的生物质（<20g）。干燥步骤在45℃的对流烘箱中进行 °C（试验方法B）或冷冻干燥（试验方法C）。 4.3 制备方法A、B和C不适用于已经通过20目筛或无法通过所述方法干燥至总固体含量大于85的材料 %, 基于烘箱干燥的重量。 4.4 制备方法A将研磨材料分为两个部分，一个−20/+80目部分和一个−80目部分。 4.4.1 外来无机物质将积聚在−80目馏分中，应独立于−20/+80目馏分进行分析。 然后，可以将这两个分数的加权结果组合起来，以“收到”为基础获得材料的结果。 注2: 在分析过程中，−80目馏分的非常精细的稠度可能会导致过滤操作出现问题，应适当处理。 4.5 制备方法D-- 方法适用于谷物、谷物发酵醪、谷物发酵啤酒和谷物发酵残渣一般稳定的谷物。 4.6 制备方法E-- 适用于具有生物或酶活性的谷物、谷物发酵泥、谷物发酵啤酒和谷物发酵残渣的方法。

1.1 This practice covers a reproducible way to convert hardwoods, softwoods, herbaceous materials (such as switchgrass and sericea), agricultural residues (such as corn stover, wheat straw, and bagasse), wastepaper (such as office waste, boxboard, and newsprint), cellulosic feedstocks pretreated to improve suitability for fermentation, cereal grains, cereal grain fermentation mash, cereal grain fermentation beer, and fermentation residues into a uniform material suitable for compositional analysis. This practice is intended for samples that need to be dried prior to analysis. 1.2 Milling and sieving actions both produce large amounts of dust. This dust can be a nuisance hazard and irritant. Use appropriate respiratory protection as needed. If excessive amounts of dust are allowed to become airborne a potential explosion hazard is possible. Provide appropriate dust control measures as needed. 1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard. 1.4 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. 1.5 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 Preparation Method A— Method suitable for the preparation of large quantities (>20 g) of field collected samples into a form appropriate for compositional analysis. Woody samples must first be available as chips of a nominal 5 cm by 5 cm by 0.6 cm (2 in. by 2 in. by 1 / 4 in.) or less and twigs not exceeding 0.6 cm ( 1 / 4 in.) diameter. Herbaceous materials may be processed as whole straw. It is recommended that wastepaper should be shredded into pieces less then 1 cm ( 1 / 2 in.) wide. Furthermore, it is recommended that twigs, straw, and wastepaper should not exceed 61 cm (24 in.) in length to facilitate handling. 4.2 Preparation Methods B and C— Methods are suitable for very moist feedstocks, samples that would not be stable during prolonged exposure to ambient conditions, or for drying materials when room conditions deviate from the ambient conditions described in 3.1.2 . These test methods are also suitable for handling small samples of biomass (<20 g). The drying step is done in a convection oven at 45 °C (Test Method B) or by lyophilization (Test Method C). 4.3 Preparation Methods A, B, and C are not intended for materials that will already pass through a 20 mesh sieve or that cannot be dried by the described methods to a total solids content of greater than 85 %, based on an oven dried weight. 4.4 Preparation Method A will separate the milled material into two fractions, a −20/+80 mesh fraction and a −80 mesh fraction. 4.4.1 Extraneous inorganic materials will accumulate in the −80 mesh fraction and it should be analyzed independently from the −20/+80 mesh fraction. Weighted results from the two fractions can then be combined to obtain results for materials on an "as received" basis. Note 2: During analysis, the very fine consistency of the −80 mesh fraction may cause problems in filtering operations and should be handled appropriately. 4.5 Preparation Method D— Method suitable for cereal grains, cereal grain fermentation mash, cereal grain fermentation beer, and cereal grain fermentation residues that are generally stable. 4.6 Preparation Method E— Method suitable for cereal grains, cereal grain fermentation mash, cereal grain fermentation beer, and cereal grain fermentation residues that are biologically or enzymatically active.