There are 7 common indoor air formaldehyde detection methods:
1. AHMT spectrophotometry: determination of formaldehyde concentration in air of residential areas and public places by AHMT(4-amino-3-diazo-5-sulfate-1, 2, 4-triazole) spectrophotometry.The measurement range is 0.01~0.16mg/m3.
2. Phenol reagent spectrophotometry: the phenol reagent (MBTH) spectrophotometry applicable to formaldehyde concentration in the air of public places, with the measuring range of 0.01~0.15mg/m3.
3. Gas chromatography.
4, acetylacetone spectrophotometry: determination of formaldehyde in industrial waste gas and ambient air of acetylacetone spectrophotometry, the use of this law with the manufacture, coating, synthetic resins, plastics, rubber, dyes, pharmaceutical, paint, leather and other industries of emissions and do medical disinfection, antisepsis, fumigation of formaldehyde determination of steam.The measurement range is 0.5~800mg/m3.
5. Electrochemical sensor method: the sample gas pumped by the pump passes through the electrochemical sensor. Formaldehyde gas molecules controlled by diffusion and absorption are oxidized under appropriate electrode voltage.The minimum detected mass concentration is 0.01mg/m3.
6. Water extraction method: water extraction method for the determination of free formaldehyde content in textiles.Applicable for textiles with free formaldehyde content between 20mg
Vapor absorption method: a vapor absorption method for the determination of formaldehyde content in textiles.Applicable for textiles with free formaldehyde content between 20mg
The detection methods of formaldehyde gas can be roughly divided into two types according to the accuracy:
1. Precision measurement (instrumental analysis), including HPLC, dnph-gc and spectrophotometry recommended by who.
2. Simple determination method, which is mainly used for rapid detection, with low accuracy requirements.There are mainly electrical methods, which can display the measurement data, as well as the detection tube method and the measurement paper method. In other words, the gas concentration can be measured by detecting the color change of the gas and indicator.