Tender for Supply, installation, commissioning and training of a microwave digestion system for Mars 6, CEM. The object also includes one year of warranty. This tender is aligned with the objectives of the project "Impact of groundwater discharge on CH4 emissions from thaw lakes (PermaFlow)", with reference PID2023-148093NB-I00, funded by MCIU/COF/AEI. IP: Carolina Olid Garcia (granting aid to "knowledge generation projects" and actions for the training of predoctoral research personnel associated with these projects, within the framework of the national program to promote scientific-technical research and its transfer, of the national research scientific, technical and innovation plan 2021-2023) and aims to study the impact of groundwater on CH4 and CO2 emissions in ponds.