Atmospheric gas–particle partitioning of E-EHMC and Z-EHMC estimated from their liquid vapour pressures at 298.15 K

Abstract

The UVB filter E-ethylhexyl p-methoxycinnamate (E-EHMC) is extensively used as UV protectant in commercial products. Besides, it is well known that it photoisomerises into Z-EHMC. In this work, ΔvapH (Tm) and vapour pressure, P (Pa) at 298.15 K, of E-EHMC and Z-EHMC were estimated using an indirect experimental method developed in our laboratory named effusion method under atmospheric pressure (EMAP). The atmospheric particle bound fraction (Φ) and the gas–particle partition coefficient (KP) for E-EHMC and Z-EHMC were derived from the vapour pressure, P (Pa) (298.15 K), estimated by EMAP methodology.