1.1 该试验方法包括在线测定水中总碳（TC）、无机碳（IC）和总有机碳（TOC），范围为0.5μg/L至50000μg/L的碳。更高的碳水平可以通过适当的在线稀释来确定。该试验方法利用紫外线过硫酸盐氧化有机碳与CO 2. 选择性膜回收CO 2. 加入去离子水中。使用校准数据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。电导率测量和碳浓度之间的关系可以用一组CO化学平衡的化学计量学方程来描述 2. ，HCO 3. − H + ，和OH − ，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，从而导致该方法在所述TOC范围内的线性响应。参见测试方法 D4519 关于CO测量的讨论 2. 通过导电性。 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独立于有机碳测定样品中的IC。CO将电导率检测器与样品隔离 2. 选择性膜在干扰最小的情况下产生非常稳定的校准。 1.3 该测试方法成功地用于掺有碳酸钠和各种有机化合物的试剂水。 该测试方法对去离子水样品和高离子强度样品都有效。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。入口系统通常限制可以引入的颗粒的最大尺寸。过滤也可以用于去除颗粒，然而，如果颗粒含有有机碳，这可能导致有机碳的去除。 1.5 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。 1.6 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。 1.7 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 该试验方法可用于检测和测定各种来源的水中的有机和无机碳杂质，包括工业用水、饮用水和废水。 5.2 这些杂质的测量对电力、制药、半导体、饮用水处理和废物处理等各个行业的运营至关重要。半导体和电力应用需要测量非常低的有机碳水平（TOC＜1μg/L）。制药行业的应用范围从USP纯化水（TOC＜500μg/L）到清洁应用（500μg/L＜TOC＜50000μg/L）。 饮用水的浓度范围为<100μg/L至25000μg/L及更高。这些应用中的一些可以包括具有大量离子杂质的水以及有机物。 5.3 无机碳和总有机碳的测量在某些应用中非常重要，例如在电力工业中。 5.4 对这些测量结果趋势的持续监测和观察有助于指示设备调整或水净化程序校正的必要性。 5.5 有关本试验方法重要性的更多信息，请参阅参考文献部分。

1.1 This test method covers the on-line determination of total carbon (TC), inorganic carbon (IC), and total organic carbon (TOC) in water in the range from 0.5 μg/L to 50 000 μg/L of carbon. Higher carbon levels may be determined by suitable on-line dilution. This 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 using calibration data. 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 can be described by a set of chemometric equations for the chemical equilibrium of CO 2 , HCO 3 − , H + , and OH − , 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 resulting in linear response of the method over the stated range of TOC. See Test Method D4519 for a discussion of the measurement of CO 2 by conductivity. 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, the use of two measurement channels allows determination of IC 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 carbonate and various organic compounds. This test method is effective with both deionized water samples and samples of high ionic strength. 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 inlet system generally limits the maximum size of particles that can be introduced. Filtration may also be used to remove particles, however, this may result in removal of organic carbon if the particles contain organic carbon. 1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.6 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. 1.7 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 useful for detecting and determining organic and inorganic carbon impurities in water from a variety of sources including industrial water, drinking water, and waste water. 5.2 Measurement of these impurities is of vital importance to the operation of various industries such as power, pharmaceutical, semiconductor, drinking water treatment, and waste treatment. Semiconductor and power applications require measurement of very low organic carbon levels (TOC < 1 μg/L). Applications in pharmaceutical industries range from USP purified water (TOC < 500 μg/L) to cleaning applications (500 μg/L < TOC < 50 000 μg/L). Drinking waters range from <100 μg/L to 25 000 μg/L and higher. Some of these applications may include waters with substantial ionic impurities as well as organic matter. 5.3 Measurement of inorganic carbon as well as total organic carbon is highly important to some applications, such as in the power industry. 5.4 Continuous monitoring and observation of trends in these measurements are of interest in indicating the need for equipment adjustment or correction of water purification procedures. 5.5 Refer to the Bibliography section for additional information regarding the significance of this test method.