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Author: Subject: agar agar resistance to sodium hydroxide
macckone
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sad.gif posted on 22-11-2014 at 22:11
agar agar resistance to sodium hydroxide


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]
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CHRIS25
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[*] posted on 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





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macckone
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[*] posted on 23-11-2014 at 09:50


Yes that is part of the processing to improve gel characteristics.
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