TOC detection method of TOC analyzer
Ultraviolet oxidation processThe UV lamp is used to irradiate the water sample to be tested, and water is decomposed into hydroxyl and hydrogen groups. The hydroxyl and oxide combine to produce CO2 and water, and then detect the newly generated CO2 to calculate the total organic carbon content. In the use of ultraviolet oxidation process, by adding titanium dioxide, persulfate and so on, can improve oxidation capacity. The advantage of UV oxidation is its high oxidation efficiency and simple maintenance. The disadvantage is that the UV lamp needs to be replaced regularly.
Determination principleThe total organic carbon (TOC) was determined by a specialized instrument, the total organic carbon analyzer (hereinafter referred to as TOC analyzer). TOC analyzer is to oxidize the total organic carbon in aqueous solution to carbon dioxide and determine its content. By using the corresponding relationship between carbon dioxide and total organic carbon, the total organic carbon in water solution was quantitatively determined.There are common TOC analyzer has two basic functions: first, the total organic carbon oxidation in water, carbon dioxide CO2; second, CO2. of different brands and types of TOC analyzer test is the difference between the new different methods to realize the two basic function. Oxidation technology commonly used are: combustion oxidation, ultraviolet oxidation and supercritical oxidation; and the detection method of CO2 is divided into: non dispersive infrared detection, direct conductivity detection and selective film conductivity detection.
Combustion oxidation processThe combustion oxidation non dispersive infrared absorption method is just a one-time conversion, simple process, good reproducibility, high sensitivity, the disadvantage is frequent detector calibration, large volume and long preheating time, must use acid, catalyst and carrier gas.The TOC analyzer consists of the following parts: the inlet, inorganic carbon and organic carbon oxidation reactor (or total carbon oxidation reactor), gas-liquid separator, non dispersive infrared CO2 analyzer, data processing.Combustion oxidation non dispersive infrared absorption method, according to the principle of measuring TOC value, can be divided into two types of subtraction and direct methods.
