how to measure pH of low amounts? - without pH strips or general pH meters? (Sep/25/2008 )
is there any other instrument invented to give precise pH of very low amounts of solutions? like having a small and narrow electrode which can give pH of even 100ul ? 
there are a couple of solutions to your question.
if you want to use your standard pH meter with a standard type of electrode then you can get a microelectrode from microelectrodes, inc.
you can get a solid state (isfet) electrode (with a special or standard pH meter) like from sentron.
there are other manufacturers of solid state electrodes as well.
if you want to use your standard pH meter with a standard type of electrode then you can get a microelectrode from microelectrodes, inc.
you can get a solid state (isfet) electrode (with a special or standard pH meter) like from sentron.
there are other manufacturers of solid state electrodes as well.
wow, mdfenko....thanks, I had missed your answer. but the microelectrodes.com address doesn't open.
I found this on biology online too
microelectrode
An electrode, with tip dimensions small enough (less than 1m) to allow nondestructive puncturing of the plasma membrane. This allows the intracellular recording of resting and action potentials, the measurement of intracellular ion and pH levels (using ion selective microelectrodes) or microinjection. Microelectrodes are generally pulled from glass capillaries and filled with conducting solutions of potassium chloride or potassium acetate to maximise conductivity near the tip. Electrical contact, if required, is usually made with a silver chloride coated silver wire.
the microelectrodes, inc. link seems to work intermittently. when i just tried it, it didn't work. then i used the same address from my bookmarks and it worked. then i tried the link again and it worked. very puzzling...
you may have to try the link a couple of times to get it to work.
the microelectrodes from this company are just very small electrodes for use in low volumes (although they may be able to fabricate intracellular electrodes).