Sea salt particles containing NaCl are the largest source of tropospheric aerosol particulate matter with 1012 kg introduced into the WAY 207024 from wave action over the oceans each year (Weis and Ewing, 1999). NO2 is one of the major pollutants in vehicle exhaust (Lawrence and Crutzen, 1999). In coastal cities with severe vehicle exhaust pollution, considerable attention has been paid to heterogeneous reactions between NaCl and NO2, and their possible roles in atmospheric chemistry (Finlayson-Pitts and Hemminger, 2000, Karlsson and Ljungstr?m, 1995 and Rossi, 2003). The heterogeneous reaction of NO2 on the surface of NaCl has been an intense research area of recent physical chemistry using X-ray photoelectron spectroscopy (Laux et al., 1996), infrared spectroscopy (Finlayson-Pitts, 1983, Vogt and Finlayson-Pitts, 1994, Weis and Ewing, 1999, Ye et al., 2010 and Yoshitake, 2000) and Raman spectroscopy (Scolaro et al., 2009). All kinetic studies clearly show L-dopa the reaction is second order with respect to NO2, but there remains the issue of whether the reactive molecule is NO2 or its dimer, N2O4.