1.1 本规程规定收集高、中或低悬浮固体的水样，以确定微塑料颗粒和纤维的存在、数量、聚合物类型和物理特性。该采集实践已在饮用水、地表水、废水流入和流出（二级和三级）以及海水的样本采集中得到验证。这种做法不限于这些特殊的水基质；然而，必须证明该实践对其他含水基质的适用性。 1.2 水样通过适当筛孔大小的过滤器或筛子，以捕获所需的最小颗粒尺寸。对于悬浮固体含量高或中等的水，应使用一系列筛孔尺寸越来越小的筛子，以防止堵塞，并允许收集所需的粒径分数。 1.3 随后的样品制备，然后利用热解气相色谱/质谱（Py-GC/MS）、红外光谱或拉曼光谱进行分析，可用于确定微塑料颗粒/纤维的数量（质量或计数）和组成（聚合物类型）。光谱法可以提供样品中存在的颗粒和纤维的数量，Py GC/MS可以提供样品中存在的质量。如果需要，可以使用适当的仪器，如扫描电子显微镜（SEM），确定微塑料颗粒/纤维的尺寸、形状和表面特征。 1.4 单位- 除非美国标准设备以英制单位（例如英寸和加仑）指定，否则以国际单位制表示的数值应视为标准。本标准不包括其他计量单位。 1.5 标准实践- 本实践提供了一组用于执行一个或多个特定操作的说明。这种做法不能取代教育或经验，应与专业判断结合使用。并非本惯例的所有方面都适用于所有情况。本实践并不代表或取代必须根据其判断给定专业服务是否充分的谨慎标准，也不应在不考虑项目的许多独特方面的情况下应用本实践。 1.6 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户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。 1.7 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）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》中确立的国际公认标准化原则制定的。 ====意义和用途====== 5.1 当水样（高悬浮固体）中存在大量无机或有机材料时，可以掩盖微塑料颗粒/纤维，并阻碍对塑料颗粒/纤维进行可靠识别和定量分析的能力。 5.2 为了量化废水进水（高悬浮固体）中微塑料颗粒/纤维的出现，采样程序必须能够在所需的24小时内以恒定流量可靠地收集样品- 小时间隔，以反映日流量的变化。对于废水进水，在24小时间隔内（约1440 gal或总5450 L）的捕获流速应不小于1 GPM，以最小化悬浮固体的不均匀性问题，并减少标准误差（样本量越大，标准误差越小）。 5.3 为了量化本规程中无机或有机物质含量较低的所有其他水样中微塑料颗粒/纤维的出现情况（低至中等悬浮固体），应通过适当的过滤器或筛子过滤最小体积为1500 L（约400 gal）的悬浮固体，以尽量减少悬浮固体不均匀性的潜在问题，并减少标准误差（样本量越大，标准误差越小）。 5.4 保留在筛子上的微塑料颗粒/纤维适用于表征尺寸、形状、数量和组成（聚合物类型），具体取决于所选的分析方法。

1.1 This practice provides for the collection of water samples with high, medium, or low suspended solids to determine the presence, count, polymer type, and physical characteristics of microplastic particles and fibers. This collection practice has been validated for the collection of samples from drinking water, surface waters, wastewater influent and effluent (secondary and tertiary), and marine waters. This practice is not limited to these particular water matrices; however, the applicability of this practice to other aqueous matrices must be demonstrated. 1.2 Water samples are passed through filters or sieves of adequate mesh size to enable capture of the smallest desired particle size. For waters with high or medium suspended solids content, a series of sieves with increasingly smaller mesh size should be used to prevent clogging and allow for the collection of desired particle size fractions. 1.3 Subsequent sample preparation followed by analysis utilizing either Pyrolysis gas chromatography/mass spectrometry (Py-GC/MS), IR spectroscopy, or Raman spectroscopy may be used to identify the quantity (mass or number count) and composition (polymer type) of microplastic particles/fibers. The spectroscopic methods can provide a count of the number of particles and fibers present in a sample, and Py-GC/MS can provide the mass present in a sample. When desired, microplastic particle/fiber size, shape and surface characteristics can be ascertained with appropriate instruments such as a scanning electron microscope (SEM). 1.4 Units— The values stated in SI units are to be regarded as the standard except where standard U.S. equipment is specified in imperial units, for example, inches and gallons. No other units of measurement are included in this standard. 1.5 Standard Practice— This practice offers a set of instructions for performing one or more specific operations. This practice cannot replace education or experience and should be used in conjunction with professional judgment. Not all aspects of this practice may be applicable in all circumstances. This practice is not intended to represent or replace the standard of care by which the adequacy of a given professional service must be judged, nor should this practice be applied without consideration of a project’s many unique aspects. 1.6 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. 1.7 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 When significant quantities of inorganic or organic material are present in water samples (high suspended solids), microplastic particles/fibers can be masked and the ability to conduct reliable identification and quantification analyses of the plastic particles/fibers can be impeded. 5.2 In order to quantify the occurrence of microplastic particles/fibers in wastewater influent (high suspended solids), the sampling procedure must be able to reliably collect samples at a constant flow over the desired 24-hour interval to reflect changes in diurnal flow. For wastewater influent the capture flow rate should be no less than 1 GPM over the 24-hour interval (approximately 1440 gal or 5450 L total) to minimize the problem with heterogeneity of the suspended solids and to reduce the standard error (the larger the sample size, the smaller the standard error). 5.3 In order to quantify the occurrence of microplastic particles/fibers in all other water samples with a lower content of inorganic or organic material present addressed by this practice (low to medium suspended solids), a minimum volume of 1500 L (approximately 400 gal) should be filtered through the appropriate filters or sieves to minimize potential issues with heterogeneity of suspended solids and to reduce the standard error (the larger the sample size, the smaller the standard error). 5.4 Microplastic particles/fibers retained on the sieves are suitable for characterization in terms of size, shape, quantity, and composition (polymer type), dependent upon the chosen analytical method.