Determination of Diphenylamine Antioxidants in Wastewater/Biosolids and Sediment

Diphenylamine derivatives are widely used as antioxidant additives in vehicle engine oils, commercial/industrial lubricants, and products composed of rubber. Their presence in the environment results primarily from human activity, and there are no known environmental measurements of these substances in any media. In this study, 17 components of three diphenylamine substances, 2-propanone, reaction products with diphenylamine (PREPOD), 1,4-benzenediamine, N,N'-mixed phenyl and tolyl derivatives (BENPAT), and benzenamine, N-phenyl-, reaction products with styrene and 2,4,4-trimethylpentene (BNST), were identified and quantified from their associated technical mixtures by Fourier transform ion cyclotron resonance mass spectrometry and flame ionization detection, and a method was developed for the determination of their presence in wastewater, biosolids, and sediment samples using gas chromatography-tandem triple-quadrupole mass spectrometry. The methods were applied to the analysis of influent, effluent, and biosolid samples, and the sums of all of the diphenylamine derivative components were 58.3-72 ng L-1, 1.48-27.1 ng L-1, and 226-1202 ng (g of dry weight)(-1), respectively. Nine sediment samples collected in Ontario, Canada, contained the sum concentrations of the target compounds ranging from 1 to 1000 ng (g of dry weight)(-1). To the best of our knowledge, this is the first work to report PREPOD, BENPAT, and BNST compounds in environmental samples.