A method for the preparation of a highly polarized nuclear spins containing sample of an organic or inorganic material, containing H or OH groups or adsorbed water molecules. Such highly polarized nuclear spins containing samples can be subjected to nuclear magnetic resonance (NMR) measurement and/or can be thawed and immediately administered to an individual undergoing a magnetic resonance imaging (MRI) scan. The method is based on generating unstable radicals on the surface of the sample in the presence of ionized environment followed by cooling the sample to cryogenic temperatures. A device for carrying out a particular step of said method is also discloses.