Experimental study for the identification of the nascent product of OH heterogeneous reaction with NaCl using chemical ionization mass spectrometry

An experimental study on the nascent product of the OH heterogeneous reaction with NaCl was performed under dry and wet conditions using a bead-filled flow tube system coupled to a high-pressure chemical ionization mass spectrometer. The ozone concentration in the flow tube for the atomic hydrogen removal was varied in order to control the conversion reaction of molecular chlorine into HCl for the identification of the nascent product. The mass spectrometric observation was that the O₃ introduction reduced the concentration HCl, while it increased the concentration of Cl₂ and ClO. Based on the experimental results, we suggest that the nascent product of the titled reaction is gaseous Cl₂, which is followed by fast conversion into HCl in presence of H. No significant difference in the concentration profile between under dry and wet (RH = 2%) conditions was observed.