An absorption badge for passive sampling of aldehydes and ketones in air has been developed. Carbonyl compounds are trapped by reaction with 2,4-DNPH. Separation and quantification of the trapped compounds is performed with HPLC. Preparation and application of the badges for the determination of formaldehyde concentrations show that the amount of formaldehyde trapped by the badge increase linearly for exposure times of 6 to 72 h. For a 6 h exposure rate, the mass of trapped formaldehyde increased linearly from 0 to 2500 ppb. The sampling rate of the badge was determined experimentally to be 1.96 ug/ppm/h, allowing direct calculation of the air concentration when the trapped amount of formaldehyde is determined. The detection limit of the sampling method is 5 ppb for a 24 h exposure. Results of replicate determinations are both repeatable and reproducible; coefficients of variation were less than 5 %. The badges provide a simple and cheap, but accurate, method for sampling formaldehyde in cabinets and showcases.
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