Continuous fluorescence determination of formaldehyde in air Original Research Article

A flow method for the determination of formaldehyde in air is presented. A cylindrical wet effluent diffusion denuder (CWEDD) is used for continuous collection of formaldehyde from air into distilled-deionized water as denuder liquid. Collected formaldehyde in the denuder concentrate is on-line determined by fluorescence 2,4-pentandione method. The collection efficiency of HCHO is quantitative at the air flow rate of 0.5 l min−1. The calibration graph is linear in the range 2–300 μg m−3 HCHO. The limit of detection is 1.6 μg m−3 HCHO. The relative standard deviations for 2 × 10−6 and 1 × 10−5 M HCHO are 2.57 and 1.06%, respectively. Acetaldehyde, acetone, formic acid and acetic acid do not interfere. Delay of the signal is 2.5 min.