Book says TOC analyzer - Shimadzu takes you to listen to the book

TOC analyzer equipment

The methods for determining TOC and CODCr are different. The determination of CODCr is carried out using a strong oxidant and heating reflux method, which can only partially oxidize the organic matter in water (with a low oxidation rate, generally 80-90%, and even lower for complex organic compounds such as polycyclic aromatic hydrocarbons), and the determination time is relatively long. Even though some rapid measuring instruments (using colorimetric methods) simplify the operation process, the determination time is still over 2 hours;

The determination of TOC is carried out using combustion or photocatalytic methods, which can completely oxidize organic matter in water. Therefore, TOC is more direct than CODCr in representing the total amount of organic matter in water, and the measurement time is shorter (less than 10 minutes can be used to determine a sample). The precision and accuracy of its measurement results are higher than those of CODCr.

The determination of total organic carbon (TOC) is carried out using the combustion method, which can completely oxidize organic matter. Therefore, it is often used to evaluate the degree of organic pollution in water bodies, and the results are expressed in terms of the content of organic carbon in the water body, regardless of oxygen consumption.

Chemical Oxygen Demand (CODCr) is an indicator of the relative content of organic matter in water, which represents the degree of pollution caused by reducing substances in water using the amount of oxygen consumed.

TOC analyzer equipment

Measurement method;

1. Direct measurement method

Pre acidify the water sample, introduce nitrogen gas for aeration, remove various carbon dioxide generated by carbonate decomposition, and then inject it into the instrument for measurement. During the aeration process, the loss of volatile organic compounds can cause errors, so the measurement result is the carbon value of the organic compounds that cannot be blown out.

2. Subtraction method

Injecting the same amount of water sample into a high-temperature furnace (900 ℃) and a low-temperature furnace (150 ℃) respectively, the organic carbon and inorganic carbon in the water sample will be converted into carbon dioxide, and the organic matter in the quartz tube of the low-temperature furnace cannot be decomposed and oxidized. The difference between total carbon (TC) and inorganic carbon (TIC) measured in high and low temperature furnaces is called total organic carbon (TOC).

Application field

Petrochemical industry: water quality monitoring and production process leak detection of circulating water, recycled water, and condensate water
Environmental Protection Industry: Monitoring of Key Pollution Source Wastewater Discharge
Water conservancy industry: water quality monitoring of surface water, Rivers and Lakes
Municipal industry: water quality monitoring of drinking water sources, water quality monitoring of incoming water from waterworks, and water quality monitoring of incoming and outgoing water from sewage treatment plants
Power industry: management of steam condensate leak detection and monitoring of high-purity water process control
Metallurgical industry: monitoring of recycled water quality in the circulating water system
Research and Education: Monitoring of Organic Matter Load in Water Bodies during the Development of Water Treatment Processes or Water Quality Research
Electronics industry: High purity water quality control and monitoring in the production process of semiconductors, chips, and integrated circuits

technical indicators

·Measurement principle: catalytic oxidation combustion+non dispersive infrared (NDIR) CO2 gas detection
·Combustion temperature: 680 ℃
·Automatic calibration: using zero standard solution and span standard solution for automatic calibration or 5-point standard solution for calibration
·Measurement range: 0-1ppm, 0-5ppm to 0-20000ppm variable
·Measurement cycle: The smallest cycle is 4 minutes
·Carrier gas: 250-300kPa high-purity nitrogen, 99.99% or more
·Sample pre-treatment function: Integrated high-speed rotary homogenizer, using tap water to automatically backwash and clean the filter screen
·Automatic cleaning function: According to the time interval set by the user, the internal pipeline of the instrument can be cleaned with distilled water at regular intervals
·Operating interface: Color touch screen
·Communication: Digital MODBUS RS232 or RS485, analog quantity, switch quantity.