Hi,my question is about the tip potential often associated with the use of glass microelectrodes.
I read the book of "Ion-Selective Microelectrodes" by Daniel Admmann (a classic textbook for ion-selective electrodes), which said in Chapter 6 that tip potential (or tip potential variations, either way) is absent in a glass reference microelectrode filled with a non-selective ion exchanger resin.
On this remark, Dr. Admann cited the early work of Thomas and Cohen (Pflugers Arch, 1981, vol 390, p-96-98), in which a reference liquid ion exchanger electrode was constructed and tested for longer stability.
I read the original paper of Thomas and Cohen (1981), and did not find any evidence that supports this claim (that the reference liquid ion exchanger electrode is free of tip potential (variations). I was lost as to where Dr. Admann drew this conclusion from.
So, could someone enlighten me as to (i) whether any typical ion-selective microelectrode also have a tip potential? (my guess is yes, but I am not sure), and (ii) could filling the electrode tip with a liquid ion exchanger resin really get rid of the tip potential problem?
Many Thanks
Hello Kevin C Chen
please check pdf and link
www.utdallas.edu/~tres/microelectrode/microelectrodes_ch11.pdf
Hi Nirmala:
Thank you for the PDF files (In fact, I already had the electronic file of the ISM chapter from UT-Dallas website). Unfortunately, they do not address the tip potential issue and hence not answer my question.
The tip potential of glass microelectrodes was first addressed by R. H. Adrian in 1956, and is often neglected nowadays in the application of ISM in a dynamic environment with constant ionic shifts.
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