The main differences and similarities between UV oxidation + conductivity test TOC and UV spectrum test TOC
Release time:2025.11.28
The main differences and similarities between UV oxidation + conductivity test TOC and UV spectrum test TOC
Total organic carbon (TOC) refers to the total amount of carbon in dissolved and suspended organic matter in water. UV oxidation + conductivity test TOC and UV spectroscopy test TOC are two common TOC measurement methods. Their main similarities and differences are as follows:
Similarities
·Purpose of measurement: Both are to determine the total organic carbon (TOC) content in the sample to evaluate the overall level of organic matter in the sample. They are widely used in water quality monitoring, environmental analysis, pharmaceuticals, food and beverages and other fields to determine the purity of the sample or the degree of organic contamination.
·Response principle to organic matter: Both are based on the absorption characteristics of organic matter to ultraviolet rays of a specific wavelength. In the UV oxidation + conductivity test, ultraviolet light is used to oxidize organic matter and convert it into carbon dioxide. The generated carbon dioxide is then detected by the conductivity method to indirectly determine TOC; UV spectroscopy directly uses the absorption of ultraviolet light by organic matter to calculate the TOC content by measuring the absorbance. Both use the optical properties of organic matter in the ultraviolet band.
Differences
·Measurement principle
·Ultraviolet oxidation + conductivity test: First, the energy of ultraviolet light is used to oxidize the organic matter in the water and convert it into carbon dioxide. Then, the amount of carbon dioxide generated is calculated by measuring the change in the conductivity of the solution before and after the reaction, and then the TOC content in the sample is obtained. Because carbon dioxide dissolves in water to form carbonic acid, carbonic acid will ionize ions, thereby changing the conductivity of the solution. This indirect method can be used to achieve quantitative analysis of TOC.
·UV spectral test: Based on the Lambert-Beer law, when a beam of parallel monochromatic light passes vertically through a uniform non-scattering absorbing substance, its absorbance is proportional to the concentration of the absorbing substance and the thickness of the absorption layer. Organic matter has a specific absorption peak in the ultraviolet region. By measuring the absorbance of the sample at a specific wavelength and comparing it with a standard sample of known concentration, the TOC content in the sample can be calculated.
·Instrument
·Ultraviolet oxidation + conductivity test: The instrument usually consists of a UV oxidation reactor, a conductivity detector, an injection system, a control system, and other parts. The UV oxidation reactor is the core component, providing UV irradiation to achieve the oxidation of organic matter; the conductivity detector is used to accurately measure the change in solution conductivity.
·UV spectral test: The main instrument is a UV-visible spectrophotometer, including light source system, monochromator system, sample cell, detector and other components. The composite light emitted by the light source is split by the monochromator to obtain light of a specific wavelength to irradiate the sample in the sample cell. The detector is responsible for detecting the light intensity after passing through the sample and converting it into an electrical signal for data processing.
·Sample requirements
·UV oxidation + conductivity test: The sample needs to be pre-treated by filtration to remove suspended matter and particulate matter to prevent it from affecting the uniformity of the oxidation reaction and the accuracy of the conductivity measurement. For some samples containing high concentrations of salt or other interfering ions, appropriate dilution or pretreatment may be required to reduce interference with conductivity measurement.
·UV spectral test: The sample should be kept clear and transparent, avoiding turbidity or suspended matter, otherwise it will cause light scattering and affect the accuracy of absorbance measurement. At the same time, the concentration of the sample needs to be within the detection range of the instrument. For samples with too high concentrations, dilution treatment is required; for samples with too low concentrations, enrichment and other methods may be required for pretreatment.
· Measurement range and accuracy
· UV oxidation + conductivity test: The measurement range is wide, and it can detect TOC samples with low concentrations from trace TOC to TOC samples with higher concentrations. It is generally suitable for TOC content ranging from a few micrograms/liter to thousands of milligrams/liter. Its accuracy is relatively high, reaching the microgram/liter level, especially for the measurement of low-concentration TOC samples. It has good accuracy and repeatability.
· UV spectrum test: The measurement range can also cover a certain concentration range, but its accuracy varies in different concentration ranges. It usually has good accuracy in the medium concentration range. For high-concentration samples, multiple dilutions may be required for accurate measurement, while for extremely low-concentration samples, its detection accuracy may be relatively low. It is generally suitable for TOC content ranging from tens of micrograms/liter to hundreds of milligrams/liter.
·Interference factors
·UV oxidation + conductivity test: Some inorganic ions in the sample, such as chlorie ions and sulfate ions, may affect the measurement of conductivity, thereby interfering with the TOC measurement results. In addition, incomplete oxidation reactions may also lead to low TOC measurement values.
·UV spectrum test: Other absorbing substances in the sample, such as nitrates and nitrites, may absorb in the ultraviolet region, overlapping with the absorption peaks of organic matter, thereby interfering with TOC measurement. In addition, the color and turbidity of the sample will also affect the absorbance measurement.
Latest news
Catalogue
Application
About Us
Contact Us
Bebur Beijing China(Marketing &Sales)
sales@bebur-tech.com
Bebur Sichuan China
( Factory&After sales Service)
technology@bebur-tech.com
Bebur UK
info@bebur-tech.com
Tel：
E-mail：
Whatsapp：
skype：
在线客服添加返回顶部
右侧在线客服样式 1,2,3 1
图片alt标题设置： Bebur
表单验证提示文本： Content cannot be empty!
循环体没有内容时： Sorry,no matching items were found.
CSS / JS 文件放置地