On-line analyzer for aquatic VOCs (Volatile Organic Chemicals)

Abstract

The invention relates to an on-line analyzer for aquatic VOCs (Volatile Organic Chemicals) based on a purge and trap-gas chromatography principle, in particular to an instrument combined with functions of automatic sampling, purge and trap pretreatment and gas chromatography. After quantitative sampling of a water sample through an automatic sampling device, the water sample is purged through controlling purge gas, a water matrix is separated and trapped by a trap after the aquatic VOCs are purged; a flow path is switched through a switch valve, so that carrier gas of a gas chromatograph passes through the trap, the trap is instantly heated to analyze absorbed organic matters, and then the carrier gas carrying the analyzed organic matters is separated and analyzed after entering a gas chromatograph analysis module. Each module is synchronously controlled by a microprocessor of the on-line analyzer for the aquatic VOCs, control software synchronously has functions of instrument operation control, and data acquisition and processing, the uniform control is realized, and the delay and the function conflict are reduced. The on-line analyzer has the advantages of simple structure, simplicity in operation, and capability of synchronously realizing sampling, pretreatment and on-line analysis of the aquatic VOCs.

Description

technical field [0001] The invention relates to the technical field of on-line monitoring instruments, in particular to an on-line analyzer for VOCs in water. Background technique [0002] The content of volatile organic compounds (VOCs) in environmental water is low (μg / L~ng / L), easy to volatilize, and quantitative analysis is difficult. Using high-sensitivity instruments and developing new pre-processing techniques can solve this problem. [0003] The analytical instruments currently on the market are not enough to directly detect VOCs in water, so it is very critical to study the sample pretreatment process. Traditional laboratory analysis methods using liquid-liquid extraction (LLE) and solid-phase extraction (SPE) have obvious disadvantages: the former uses a large amount of organic solvents, which is prone to emulsification, requires further concentration, and has low sensitivity to volatile organic compounds; The latter process is cumbersome, and the solid-phase mic...

AI Technical Summary

Problems solved by technology

[0004] At present, some important indicators of drinking water all rely on regular on-site sampling and laboratory analysis. Due to the troublesome pre-treatment in the laboratory and the long analysis period, it is impossible to obtain a large amount of supporting data for early warning and monitoring, and it is difficult to deal with emergencies. Organic pollution incident

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