Ion
Selective
Electrodes from
Broken Glass Electrodes
The use of broken glass electrodes as indicator electrodes in potentiometric titrations of silver or halide ion has previously been reported in thls Journal.' Another use that can be made of these bmken electrodes is in the construction of ion selective electrodes. We use the procedures described by Czahan and Rechnitz2 to fabricate solid state membranes selective for Ag+, Cuz+, Phz+, Cd2+, SZ-, CI-, BI-,and I-. The membranes are placed in contact with the internal silver wire of the bmken glass electrode using silver-based conducting epoxy (Epa-Tek 410, Epoxy Technology Inc., 65 Grove Street, Watertown, Mass. 02172). A glass or inert tubing sleeve is bonded to the membrane and electrode using insulating epoxy or silicone rubber sealto prevent contact between the silver epoxy and solution. The average cost for chemicals and materials is less than $2 per electmde. The finished electmde, being completely solid state, is essentially unbreakable. Easy maintenance, inertness to oxidizing and reducing agents, versatility and excellent Nernstian response make these electrodes attractive candidates for use in student laboratories.
ELECTRODE CABLE
INERT SLEEVE SILVER WIRE SILVER EPOXY INERT EPOXY MEMBRANE
Presented in part at the Midwest Regional ACS Meeting held at Lawrence, Kansas in October of 1973. 'Davidson, John E., J. CHEM. EDUC., 50,375 (1973). 2Czaban, J. D., andRechnitz, G.A.,Anal. Chem., 45,471 (1973). University of Nebraska Lincoln. Nebraska 68508
Virgil K. Olson Robert D. Hargens James D. Carr Robert D. Larsan
Volume 51. Number 12, December 7974
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