水质.使用小型密封管测定水中硝酸盐.第2部分：变色酸显色反应

[中文适用范围]： 本文件规定了各种来源的水中硝酸盐（NO3-N）的测定方法，例如天然水（包括地下水、地表水和沐浴水）、饮用水和废水，测量浓度范围为0.20 mg /l 和 30 mg/l 的 NO3-N，采用小规模密封管法。 小型密封管方法可能需要不同的测量范围。 根据不同制造商的小型密封管方法的类型，测量范围可能有所不同。 用户可以选择适合应用范围的小规模密封管测试，或者通过初步稀释来调整浓度超过测试测量范围的样品。 注 1：小规模密封管试验的结果在试验应用范围的中间最为精确。 制造商的小型密封管方法是基于显色显色反应，取决于所使用的小型密封管的典型操作程序，见第9条。 注2：法律、法规或标准可以要求数据以NO3表示。 用第 11 条中的化学计量换算系数 4,42681 进行换算后。 注 3：在污水处理的习惯用语中以及在自动密封管测试装置的显示屏上，不带负电荷的 NO3 已成为以下常用符号：参数硝酸盐，特别是参数硝酸盐-N。 尽管不是完全正确的化学命名法，但本文件中还是采用了这种符号。 [外文原描述]： This document specifies a method for the determination of nitrate as NO 3 -N in water of various origin such as natural water (including groundwater, surface water and bathing water), drinking water and wastewater, in a measuring range of concentration between 0,20 mg/l and 30 mg/l of NO 3 -N using the small-scale sealed tube method. Different measuring ranges of small-scale sealed tube methods can be required. The measuring ranges can vary depending on the type of the small-scale sealed tube method of different manufacturers. It is up to the user to choose the small-scale sealed tube test with the appropriate application range or to adapt samples with concentrations exceeding the measuring range of a test by preliminary dilution. NOTE 1 The results of a small-scale sealed tube test are most precise in the middle of the application range of the test. Manufacturers' small-scale sealed tube methods are based on chromotropic colour reaction, depending on the typical operating procedure of the small-scale sealed tube used, see Clause 9 . NOTE 2 Laws, regulations or standards can require that the data is expressed as NO 3 after conversion with the stoichiometric conversion factor 4,426 81 in Clause 11 . NOTE 3 In the habitual language, use of sewage treatment and on the displays of automated sealed-tube test devices, NO 3 without indication of the negative charge has become the common notation for the parameter nitrate and especially for the parameter nitrate-N. This notation is adopted in this document even though not being quite correct chemical nomenclature.