The Comparison between Chemical Spectrophotometry and Instrument Method to Determine the Formaldehyde Concentration of the Indoor Air

To detect the accuracy of measurement results with Z300P portable formaldehyde analyzer, and provide scientific data for detecting formaldehyde concentration in the air using instrument instead of chemical method, the different formaldehyde concentration was detected by phenol reagent and acetyl acetone which are the national standard method for the formaldehyde concentrations determination in indoor air and their precision test and linear analysis were done. At the same time, the formaldehyde of low, medium and high concentrations of in different indoor field was detected with Z300P portable formaldehyde analyzer, then significant difference test among the results was done. The average relative standard deviation of measurement results through phenol reagent and acetyl acetone national standard method was less than 5%, there is a good linear relationship (r >; 0.997).There was no significant difference (P >; 0.05) indifferent formaldehyde concentrations results through phenol reagent with acetyl acetone method. But there was a significant difference (P <; 0.05) among the determination results coming from the chemical and instrument method. When Measurement results with phenol reagent was regarded as the "true value", the accuracy of the results in low, medium and high concentration with instrument method were 37.5%, 70% and 80%. There is a high precision and good reproducibility existing in Phenol reagent and acetyl acetone method. The measurement results using them can be used as calibration "true value." of other methods. The results with Z300P portable formaldehyde analyzer of this institute have been inaccurate. It needs maintenance and calibration, but it can also be used to rough detect airborne formaldehyde content in emergency by calibration coefficients.