【国外标准】 Standard Test Method for Determination of Microplastics Particle and Fiber Size, Distribution, Shape, and Concentration in Waters with High to Low Suspended Solids Using a Dynamic Image Particle Size and Shape Analyzer

5.1 Many microplastic particles enter the environment, including ambient waters and drinking water supplies, via wastewater sources resulting from both industrial processes and consumer products. The presence of high percentages of organic particles, including cellulose material originating from toilet paper and chitin-based materials originating from insect exoskeletons, makes visual identification and subsequent quantification of microplastic particles in wastewater difficult.5.2 This test method, associated sampling Practice D8332, and preparation Practice D8333 provide a standardized approach for the preparation of water and, particularly, wastewater samples. The isolation of microplastic particles from interfering contaminants by Practice D8333 enables positive identification and, therefore, quantification of microplastic particles.5.3 Using this test method, microplastic particles are characterized in terms of size, shape, and quantity, allowing for the enumeration of subsequent particle count for a given volume of sample. The method does not provide qualitative identification of plastic composition.1.1 This test method covers the determination of microplastic particle size distribution, shape characterization, and number concentration (particle counts) in sample extracts containing particles between 5 µm and 100 µm. Light is transmitted through a flow cell containing particles in liquid medium. The particles create shadows as they pass through the field of vision of a camera, producing a multitude of images. The images are then used to measure size, shape, and concentration.1.2 This test method is used as a complementary technique for microplastic particle and fiber polymer identification methods infrared microscopy and gas chromatography/mass spectroscopy pyrolysis.1.3 This test method requires that samples are collected according to Practice D8332 and prepared according to Practice D8333 prior to use.1.4 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.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.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.