macckone - 22-11-2014 at 22:11
Does anyone have data or a link on the resistance
of agar agar to sodium hydroxide and chlorine.
Agar agar is used in sodium hydroxide diffusion
experiments and as salt bridges. But I have not
found anything on maximum concentration
of sodium hydroxide that it can be used with.
I have also found that sodium hydroxide is used
in processing it and to improve gel characteristics.
But again no concentrations.
[Edited on 23-11-2014 by macckone]
CHRIS25 - 23-11-2014 at 01:37
At the risk of offending the more intelligent species on this forum I found this: I know it does not answer all three questions above but it comments
on concentration NaOH and contains references. NAOH comments I have outlined here for easy finding in the pdf:
..........it is necessary to make what is called a sulfate alkaline hydrolysis, working in stronger alkaline conditions to change the L-galactose
6-sulfate into 3,6-anhydro-L-galactose. For this purpose the diffusion is made with sodium hydroxide solution (at least 0.1M) for at least one hour at
a temperature between 80-97°C,
..........say the industry uses 0.25-0.5M sodium hydroxide solution at 80-90°C for 3-5 hours.
http://www.fao.org/docrep/x5822e/x5822e03.htm
macckone - 23-11-2014 at 09:50
Yes that is part of the processing to improve gel characteristics.