1. formaldehyde: phenol reagent spectrophotometry: 5mL phenol reagent solution is used to sample 10L air in the field, and formaldehyde in the air is adsorbed, and then it is brought back to the laboratory for colorimetric analysis, and the formaldehyde concentration is calculated according to the standard working curve;
2. Ammonia: Indophenol Blue Spectrophotometry: 5L of air was sampled in the field with 10mL dilute sulfuric acid solution to adsorb ammonia in the air, and then it was brought back to the laboratory for color development and colorimetric analysis, and the concentration of ammonia was calculated according to the standard working curve;
3. Benzene: thermal desorption gas chromatography: 10L air is sampled in the field, and benzene in the air is adsorbed by activated carbon tube, and then it is taken back to the laboratory for analysis by chromatograph after thermal desorption. Quantify the peak area according to the peak time and calculate the benzene concentration according to the standard working curve;
4.TVOC: thermal desorption gas chromatography, which uses Tenax-Ta tube to sample 10L air on the spot, absorbs all kinds of volatile organic compounds in the air, takes it back to the laboratory for thermal desorption, and then analyzes it with a chromatograph, quantifies the peak area according to the peak time, and calculates the total TVOC concentration according to the standard working curve;
5. Radon: field instrument determination method, commonly used instruments are RAD-7, FD2 16, etc. This is also the analysis of radon concentration after collecting air on the spot.
For offices with natural ventilation, the doors and windows should be closed 1 hour before field sampling in item 1~4 above, and the fifth item should be closed 24 hours in advance. For offices with central air conditioning, only the air conditioning needs to be turned on when sampling, and it is not necessary to seal in advance.