Method for measuring content of benzene in air

Abstract

The invention relates to a method for measuring the content of benzene in air, belonging to the field of analytical chemistry. The method for measuring the content of benzene in air has low cost and comprises the following steps of: a, sampling: adsorbing benzene in air, the volume of which is V0, with active carbon; b, desorbing: pouring the active carbon absorbing benzene into a head space sample bottle with the volume of V1, placing the head space sample bottle in a thermal desorption instrument, heating at the temperature of 330-350 DEG C for 30 min, and collecting the head space desorbing gas; and c, carrying out chromatographic analysis on the head space desorbing gas, measuring the concentration c of benzene in the head space desorbing gas, and calculating the concentration of benzene in the air according to the following formula: C=c*V1 / V0, wherein C is the concentration of benzene in the air sample, and the unit is mg / m<3>; c is the measured concentration of benzene in the head space desorbing gas, and the unit of c is mug / ml; V1 is the volume of the head space sample bottle, and the unit of V1 is ml; and V0 is the volume of the air sample, and the unit of V0 is L.

Description

technical field [0001] The invention relates to a method for measuring benzene content in air, belonging to the field of analytical chemistry. Background technique [0002] Benzene is one of the common toxic substances in many industrial and mining enterprises, and occupational diseases of benzene poisoning often occur. In addition, a certain amount of benzene will remain after interior decoration, and excessive benzene content in the air will induce various diseases. Therefore, it is of great significance to accurately and quickly determine the benzene content in the air. [0003] At present, the detection of benzene content in various industrial and mining enterprises and indoor air is mainly through the adsorption sampling of activated carbon tubes, and then the adsorbed benzene is desorbed by solvent dissolution or thermal desorption for gas chromatography determination. However, both methods have their advantages and disadvantages. The solvent desorption method is re...

AI Technical Summary

Problems solved by technology

The solvent desorption method is reliable, the equipment is simple, and it is widely used, but the solvent used is carbon disulfide, which needs to be purified, and the procedure is cumbersome and costly. If imported reagents are used, it will be more expensive

Moreover, carbon disulfide is highly toxic and harmful to the human body. In addition, the dose of carbon disulfide used in the experiment is very large. It is difficult to recycle the remaining carbon disulfide after analysis. Even if it can be processed, the cost is also very expensive. limit its application

The thermal desorption method is easy to operate, but in practical applications, the second desorption automatic sampling must be used to achieve satisfactory accuracy and reproducibility, and the thermal desorption instrument that can realize the second desorption automatic sampling is very expensive. Increases the cost of thermal desorption to some extent

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