1.1 该试验方法涵盖了水中总碳（TC）、无机碳（IC）和总有机碳（TOC）的测定，其范围为0.5 mg/L至30 mg/L的碳。更高的水平可以通过样品稀释来确定。该试验方法利用紫外线过硫酸盐氧化有机碳，再加上一氧化碳 2. 选择性膜回收CO 2. 加入去离子水中。测量去离子水的电导率变化，并将其与氧化样品中的碳浓度相关。无机碳以类似的方式测定，而不需要氧化。在这两种情况下，样品都被酸化以促进CO 2. 通过膜回收。电导率测量与碳浓度之间的关系由一组CO化学平衡的化学计量学方程描述 2. ，HCO 3. − H + ，以及离子浓度与电导率之间的关系。 化学计量模型包括平衡常数和比电导的温度依赖性。 1.2 这种测试方法具有非常高灵敏度的检测器的优点，该检测器允许对相对小体积的样品进行非常低的检测水平。此外，使用两个测量通道可以确定CO 2. 在样品中独立于有机碳。CO将电导率检测器与样品隔离 2. 选择性膜导致非常稳定的校准，干扰最小。 1.3 该测试方法成功地用于掺有碳酸氢钠和各种有机材料的试剂水。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。 1.4 该试验方法仅适用于可引入反应区的样品中的含碳物质。注射器开口尺寸通常限制可引入的颗粒的最大尺寸。 1.5 除实验室分析外，该测试方法还可用于在线监测。 1.6 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。 1.7 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。 1.8 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 该试验方法用于测定各种天然、家庭和工业来源的水中的碳含量。 在最常见的形式中，该测试方法用于测量有机碳，作为监测高纯度和饮用水中有机污染物的一种手段。这些测量也用于监测废物处理过程。 5.2 文献中描述了TOC与其他水质参数（如化学需氧量（COD）和总需氧量（TOD））的关系 ( 6. ) .

1.1 This test method covers the determination of total carbon (TC), inorganic carbon (IC), and total organic carbon (TOC) in water in the range from 0.5 mg/L to 30 mg/L of carbon. Higher levels may be determined by sample dilution. The test method utilizes ultraviolet-persulfate oxidation of organic carbon, coupled with a CO 2 selective membrane to recover the CO 2 into deionized water. The change in conductivity of the deionized water is measured and related to carbon concentration in the oxidized sample. Inorganic carbon is determined in a similar manner without the requirement for oxidation. In both cases, the sample is acidified to facilitate CO 2 recovery through the membrane. The relationship between the conductivity measurement and carbon concentration is described by a set of chemometric equations for the chemical equilibrium of CO 2 , HCO 3 − , H + , and the relationship between the ionic concentrations and the conductivity. The chemometric model includes the temperature dependence of the equilibrium constants and the specific conductances. 1.2 This test method has the advantage of a very high sensitivity detector that allows very low detection levels on relatively small volumes of sample. Also, use of two measurement channels allows determination of CO 2 in the sample independently of organic carbon. Isolation of the conductivity detector from the sample by the CO 2 selective membrane results in a very stable calibration, with minimal interferences. 1.3 This test method was used successfully with reagent water spiked with sodium bicarbonate and various organic materials. It is the user's responsibility to ensure the validity of this test method for waters of untested matrices. 1.4 This test method is applicable only to carbonaceous matter in the sample that can be introduced into the reaction zone. The injector opening size generally limits the maximum size of particles that can be introduced. 1.5 In addition to laboratory analyses, this test method may be applied to on line monitoring. 1.6 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.7 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. 1.8 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 is used for determination of the carbon content of water from a variety of natural, domestic, and industrial sources. In its most common form, this test method is used to measure organic carbon as a means of monitoring organic pollutants in high purity and drinking water. These measurements are also used in monitoring waste treatment processes. 5.2 The relationship of TOC to other water quality parameters such as chemical oxygen demand (COD) and total oxygen demand (TOD) is described in the literature ( 6 ) .