Rider, N. D.Taha, Y. M.Odame-Ankrah, C. A.Huo, J. A.Tokarek, T. W.Cairns, E.Moussa, S. G.Liggio, J.Osthoff, H. D.2021-06-292021-06-292015-07-08Rider, N. D., Taha, Y. M., Odame-Ankrah, C. A., Huo, J. A., Tokarek, T. W., Cairns, E., … Osthoff, H. D. (2015). Efficient photochemical generation of peroxycarboxylic nitric anhydrides with ultraviolet light-emitting diodes. Atmospheric Measurement Techniques, 8(7), 2737–2748. doi:10.5194/amt-8-2737-2015http://hdl.handle.net/1880/113556https://doi.org/10.11575/PRISM/46145Photochemical sources of peroxycarboxylic nitric anhydrides (PANs) are utilized in many atmospheric measurement techniques for calibration or to deliver an internal standard. Conventionally, such sources rely on phosphor-coated low-pressure mercury (Hg) lamps to generate the UV light necessary to photo-dissociate a dialkyl ketone (usually acetone) in the presence of a calibrated amount of nitric oxide (NO) and oxygen (O2). In this manuscript, a photochemical PAN source in which the Hg lamp has been replaced by arrays of ultraviolet light-emitting diodes (UV-LEDs) is described. The output of the UV-LED source was analyzed by gas chromatography (PAN-GC) and thermal dissociation cavity ring-down spectroscopy (TD-CRDS). Using acetone, diethyl ketone (DIEK), diisopropyl ketone (DIPK), or di-n-propyl ketone (DNPK), respectively, the source produces peroxyacetic (PAN), peroxypropionic (PPN), peroxyisobutanoic (PiBN), or peroxy-n-butanoic nitric anhydride (PnBN) from NO in high yield (> 90 %). Box model simulations with a subset of the Master Chemical Mechanism (MCM) were carried out to rationalize product yields and to identify side products. The present work demonstrates that UV-LED arrays are a viable alternative to current Hg lamp setups.eng© Author(s) 2015journal articleRGPIN/03849-2016http://dx.doi.org/10.5194/amt-8-2737-2015