I want to analyze the percentage of C;N;P of two different species of aquatic insects at their larval stage. But we are doing experiments at the field. So I want to know what is the best option to preserve the specimens at fieldwork (for around two days) to afterwards proceed with the stoichiometry analysis at the lab (possible send samples to an external laboratory). Any literature about it? Any laboratory where I could do that or ask?.
Thanks in advance...