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Tris Buffers vs. pH Electrodes - (Jul/25/2006 )

Hi Everyone-

I know there is issues when using some pH electrodes to test the pH of Tris buffers. I've been searching for the exact reason for this and I'm not coming up with much. Does have any good information/references for this?

Thanks Much!


most pH electrodes use a ag/agcl bridge and have agcl in the electrode solution. tris binds ag and this will throw off the reading.

you can use an electrode which has a hg/hgcl bridge and kcl fill solution (without agcl).

you can also use an isfet (solid state) electrode but be careful, some of them also use a ag/agcl bridge.

you can get this information at most websites of companies that produce and/or sell electrodes.