Inter-Comparisons of Major Ions and Organic Matter Using Aerodyne Aerosol Mass Spectrometer, Ion Chromatography and Sunset Lab Carbon Analyzer in Aged Aerosols from Okinawa in the Western North Pacific Rim

Inorganic components were measured in the aged ambient aerosols from Cape Hedo, Okinawa, an outflow region of East Asia, using online quadrupole Aerodyne aerosol mass spectrometer (Q-AMS) and offline ion chromatography (IC) Sunset Lab carbon analyzer. Here, we performed inter-comparison study on nitrate (NO3−), ammonium (NH4+) sulfate (SO42−) that by IC AMS. Sulfate showed a good agreement between two instruments. However, abundances NO3− AMS are average twice overestimated compared to obtained IC. We also found significant amount organic nitrogen (ON) was detected filter samples Okinawa. The measurement data based-NO3− need be carefully evaluated when ON is abundantly present aerosols. OM/OC ratios derived consistent with bulk OMAMS/OCSunset (2.1). This demonstrates 2.1 reasonable criteria for more