Abundances of xenon released from unexposed Murchison samples (ME 2644-1, -2, -3) by laser heating and from the Xe-exposed sample without laser heating (degassing-1) and after heating at 150°C for 48 hr (degassing-2). BLKNi1 and BLKNi2 are blank measurements obtained by laser-melting empty Ni foils and thus represent the typical maximum blank level of the analytical system used at IPGP (i.e., the purification line plus the Xe blank from the metallic foils used to wrap the samples).