A method for personal sampling and analysis of nanogram amounts of formaldehyde in air.

An air sampling and analytical system for formaldehyde measurements based on a solid sampler is described. The samplers were tested on a standard atmosphere in the range of 0.2 to 0.8 mg/m3 dry air. A single 340 mg sorbant section had without drying sections a capacity of 16 micrograms formaldehyde in dry air and 3 micrograms at 70% RH, 23 degrees C. The precision of fluorimetric analysis was better than 6% for samples of 300, 600 and 1200 ng formaldehyde, and the accuracy was better than 10%. The precision of a colorimetric analysis was 12% for a 300 ng sample and 2% for 600 and 1200 ng samples. The accuracy of this method was better than 7%. Both the fluorimetric and the colorimetric analyses are found to be accurate and sensitive analytical methods for the determination of low formaldehyde concentrations. However, if measurements of more than 15 minutes duration are taken and a dessicant is used, the accuracy still remains to be verified. Positive interference from acrolein (5-7% interference when equimolar amounts are present) was found, but there was no interference from other aldehydes.