[en] Wall coatings which have been produced for potential use in the JET project (Si, TiC, SiC, TiO₂, Al₂O₃ and MgAl₂O₄ on Inconel 600) have been exposed to laser radiation pulses (Laser Release Analysis) in order to determine (i) the concentration of absorbed or adsorbed gases in the near surface region as a function of bakeout history, and (ii) the relative trapping behaviour of sub-eV atoms, when compared with 50-1000 eV ions. Following normal system bakeout at 500 K for 24 hours, the major species released were found to be H₂ and CO, with levels up to ∼7x10¹⁶ H/cm² and ∼4x10¹⁶ CO/cm². A similar concentration of argon was found for only the TiC coating produced by sputter ion plating. A further 1-hour heating of the samples at 800-900 K resulted in a reduction of hydrogen and CO release levels by about an order of magnitude. After such preparation procedures the samples were exposed to sub-eV D⁰ atoms to fluences of ∼2x10¹⁹ D⁰/cm², and deuterium retention levels were measured to be of the order of 10¹⁴-10¹⁶ D/cm² for the various coatings. Implications of these results for JET's first-wall tritium inventory are discussed. 14 refs