On-line monitoring system and method for rapidly determining volatile organic compound with high resolution and high sensitivity

Abstract

The invention relates to an analysis and detection instrument, in particular to an online monitoring system and method for rapidly determining volatile organic compounds with high resolution and highsensitivity. The system comprises a sampling joint and a reaction chamber, wherein the sampling joint is connected with a gas filter, a precision filter, a gas-liquid separator, a permeable membrane gas dryer and a sixteen-way switching valve; the reaction chamber comprises an ion source glow discharge region, an ion source drift region, a first differential vacuum cavity and a reaction tube whichare sequentially adjacent, the rear part of the reaction chamber is sequentially connected with a second differential vacuum cavity, an ion transmission region and a TOF detection region, a single lens is arranged in the ion transmission region, and the single lens consists of three groups of electrodes which are arranged left and right; the upper portion of the TOF detection region is communicated with a reflection region through a field-free drift region, and three groups of reflectors and detectors are arranged in the reflection region. The system is wide in molecular weight measurement range, high in resolution and sensitivity, capable of detecting four decimal sites after the molecular weight reaches a decimal point, few in interference factors in the detection process, few in fragment generation, easy to analyze and capable of achieving real-time, rapid and accurate measurement of pollution source waste gas.

Description

technical field [0001] The invention relates to an analysis and detection instrument, in particular to an on-line monitoring system and method for quickly measuring volatile organic compounds with high resolution and high sensitivity. Background technique [0002] With the promulgation of the national "Ten Atmospheric Measures", the determination of volatile organic compounds (VOCs) in the air and exhaust gas has become the key content of atmospheric monitoring. The collected samples are taken back to the laboratory for analysis. This sampling method has many disadvantages: after the sample is collected, there may be adsorption of the gas sampling bag or incomplete desorption of the adsorption tube, and it is impossible to obtain the real value of the pollutants discharged by the enterprise; and the sampling time of this sampling method is often the sampling location. Enterprises know in advance, so there will be measures to interfere with the normal discharge of pollutants...

AI Technical Summary

Problems solved by technology

At present, PTR-MS, which is more developed, uses the quadrupole to screen the sample molecules after the proton transfer reaction between the sample molecules and the reaction gas, and then detects them through the detector. This method realizes the rapid detection of VOCs gases, but there are also Many problems, the use of quadrupole mass filter to screen molecules, the determination of molecular range is narrow, the detection species is limited, the mass resolution is low, the detection limit is high, and only a few VOCs molecules with small molecular weight can be detected

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