Optimization of a Solid Sorbent Dynamic Personal Air Sampling Method for Aldehydes

A solid sorbent personal dynamic air sampling method for aldehydes using chemisorption with 20 percent (w/w) O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine hydrochloride (PFBHA) on Tenax TA has been optimized for several aldehydes. The method for formaldehyde was developed after optimizationfor valeraldehyde and acrolein. The effects of temperature, intermittent exposure, and flow rate on sampling efficiency were investigated. Vapors of known concentrations were generated in Tedlar gas bags by syringe injection. Aldehyde chemisorption by reaction with 200-mg coated solid sorbent in a Pyrex Tube (7-cm length, 7-mm OD, and 5-mm ID) occurred during dynamic collection with a personal sampling pump operated at 10, 50, or 100 mL/min. The oxime derivatives were 81-87 percent desorbed by shaking with hexane for two minutes or more, resulting in coefficients of variation ranging between 4-7 percent. Aliquots were then injected for gas chromatographic analysis on a nonpolar capillary column with mass spectrometric or...