Non-thermosensitive medium for analyzing species in a channel and for minimizing adsorption and/or electroosomosic phenomena

An aqueous liquid medium for analyzing, purifying or separating species inside an element comprising walls or for treating the walls of said element, comprising:

• at least one polymer having several polymer segments that differ in chemical or topological nature, said at least one polymer being one of
• (a) an irregular block copolymer
• and
• (b) an irregular comb polymer having a polydispersity of at least 1.5 for all polymer segments of at least one type of chemical or topological nature and having side branches with a molecular mass greater than 1500;
• and
• a viscosity that does not vary by a factor of 2 or more over a temperature range of 20° C. or less between a temperature that is 10° C. higher than the solidification point of said medium and a temperature that is 10° C. lower than the boiling point of said medium,
• wherein,
• said at least one polymer has an average of at least three junction points established between polymer segments that differ in chemical or topological nature.