Hi Carme,

I suppose you want to stop mineralization as soon as possible. Just take the samples avoiding contamination by plasticizers and human contaminants including fingerprints. You can store them wet in glass vials as long as there is no water standing on it. I also used aluminum-foil but this is not a good idea for samples from salt waters since it will corrode. Label the vials (twice) with a marker and/or label that is resistant to freezing for long periods and that does not come off upon thawing. Freeze at -18°C should be OK. You may want to take volume and weight prior to freezing. Frozen samples are easy to transfer later to a freeze drier.