The Determination of Biurea in the Presence of Azodicarbonamide by HPLC

Azodicarbonamide (AOA), a solid blowing agent used in the manufacture of plastics, has been selected for inhalation toxicity testing by the National Toxicology Program. To test for decomposition of ADA during eerosollzation, an HPLC method was developed to quantitete the relative amounts of one possible degradation product, biuree, in bulk samples and filter samples collected after eerosolizatlon. The method uses a Cla column with 10-vm particles, UV monitoring at 190 nm for biurea and 425 nm for ADA, and a mobile phase of 100% water. Quantltation Is with 14C-labeled blurea and ADA as external standards. The assay was validated by spiking bulk ADA with projected levels of 1, 2, and 3% blurea. Levels of biurea bound in both bulk and filtercollected aerosol samples of ADA were both 0.50%, with relative standard deviations of 13 and 26%, respectively.