1.1 本试验方法适用于饮用水、地表水、盐水、废水和地下水中硝酸盐和亚硝酸盐（如氮）的测定。该试验方法的适用范围为0.05至5 mg/L的氮气。该范围可以通过稀释适当的等分试样而向上扩展。40 CFR第136部分方法检测限（MDL）为0.02 mg/L。 1.2 用户有责任确保该测试方法对未经测试的基质水的有效性。第节中的质量控制标准 17 对于方法空白、实验室对照样品、基质尖峰和基质重复必须满足要求。 1.3 以国际单位制表示的数值被视为标准。本标准不包括其他计量单位。 1.4 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====== 5.1 此测试方法取代方法 第1254天 （亚硝酸盐）和 1992年 （硝酸盐）。亚硝酸盐试验方法（方法 第1254天 )使用了一种被认为是潜在致癌物的试剂。硝酸盐试验方法（方法 1992年 )已被证明在废水中使用时具有相对较大的误差，并且也比本文所述的测试方法具有更大的操作难度。 5.2 此测试方法可代替测试方法 第3867页 （亚硝酸盐硝酸盐）。试验方法 第3867页 使用镉将硝酸盐还原为亚硝酸盐。镉被认为是一种有毒金属。此外，非均相镉还原剂比本试验方法中描述的还原更困难。

1.1 This test method is applicable to the determination of nitrate plus nitrite (as nitrogen) in drinking water, surface, saline, wastewater, and ground waters. The applicable range of this test method is from 0.05 to 5 mg/L of nitrogen. The range may be extended upward by dilution of an appropriate aliquot. The 40 CFR Part 136 Method Detection Limit (MDL) is 0.02 mg/L. 1.2 It is the user's responsibility to ensure the validity of this test method for waters of untested matrices. The quality control criteria in Section 17 for method blanks, laboratory control samples, matrix spikes and matrix duplicates must be met. 1.3 The values stated in SI units are regarded as standard. No other units of measurement are included in this 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 ====== 5.1 This test method replaces Methods D1254 (Nitrite) and D992 (Nitrate). The nitrite test method (Method D1254 ) used a reagent that is considered to be a potential carcinogen. The nitrate test method (Method D992 ) has been shown to have relatively large errors when used in wastewaters and also has greater manipulative difficulties than the test method described herein. 5.2 This test method can be used in place of Test Methods D3867 (Nitrite-Nitrate). Test Methods D3867 uses cadmium for the reduction of nitrate to nitrite. Cadmium is considered a toxic metal. Also, the heterogeneous cadmium reductant creates greater difficulty than the reduction described in this test method.