1.1 这些试验方法涵盖了大多数水和废水中溶解硒和总可回收硒的测定。两种试验方法均采用原子吸收程序，如下所示: 小节 试验方法A——气体氢化物原子吸收法 2. , 3. 7 – 16 试验方法B-石墨炉原子吸收光谱法 17 – 26 1.2 这些试验方法适用于无机和有机形式的溶解硒。它们也适用于颗粒形式的元素，条件是它们在适当的酸消化步骤中溶解。然而，某些含硒重金属沉积物可能不会被消化。 1.3 这些试验方法最适用于以下范围: 试验方法A——气体氢化物原子吸收法 2. , 3. 1. μg/L至20 μg/L 试验方法B-石墨炉原子吸收光谱法 2. μg/L至100μg/L 这些范围可以通过减少样本量或稀释原始样本来扩大（相应的精度损失），但通过火焰原子吸收光谱法更方便地确定远大于上限的浓度。 1.4 以国际单位制表示的数值应视为标准。括号中给出的值是对英寸磅单位的数学转换，仅供参考，不被视为标准。 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。 有关具体的危险说明，请参阅 11.12 和 13.14 . 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 在大多数天然水中，硒的浓度很少超过10μg/L。 然而，在一年中的不同时间，某些类型的含硒土壤的径流可产生高达每升几百微克的浓度。此外，工业污染可能是河流和溪流中硒的重要来源。 4.2 饮用水中高浓度的硒被怀疑对动物生命有毒。硒是一种优先污染物，所有公共水务机构都必须监测其浓度。 4.3 这些测试方法确定了据报道在大多数天然水和废水中发现的硒的优势物种，包括硒、硒酸盐和有机硒化合物。

1.1 These test methods cover the determination of dissolved and total recoverable selenium in most waters and wastewaters. Both test methods utilize atomic absorption procedures, as follows: Sections Test Method A—Gaseous Hydride AAS 2 , 3 7 – 16 Test Method B—Graphite Furnace AAS 17 – 26 1.2 These test methods are applicable to both inorganic and organic forms of dissolved selenium. They are applicable also to particulate forms of the element, provided that they are solubilized in the appropriate acid digestion step. However, certain selenium-containing heavy metallic sediments may not undergo digestion. 1.3 These test methods are most applicable within the following ranges: Test Method A—Gaseous Hydride AAS 2 , 3 1 μg/L to 20 μg/L Test Method B—Graphite Furnace AAS 2 μg/L to 100 μg/L These ranges may be extended (with a corresponding loss in precision) by decreasing the sample size or diluting the original sample, but concentrations much greater than the upper limits are more conveniently determined by flame atomic absorption spectrometry. 1.4 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. 1.5 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. For specific hazard statements, see 11.12 and 13.14 . 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 In most natural waters selenium concentrations seldom exceed 10 μg/L. However, the runoff from certain types of seleniferous soils at various times of the year can produce concentrations as high as several hundred micrograms per litre. Additionally, industrial contamination can be a significant source of selenium in rivers and streams. 4.2 High concentrations of selenium in drinking water have been suspected of being toxic to animal life. Selenium is a priority pollutant and all public water agencies are required to monitor its concentration. 4.3 These test methods determine the dominant species of selenium reportedly found in most natural and wastewaters, including selenities, selenates, and organo-selenium compounds.