User:Michael S. Bible/Notebook/571/2014/10/22

Biomaterials Design Lab

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Create an Iodide Ion Selective Electrode Prepare iodide ion selective electrodes Prepare 10 mL 3 M NaCl Carefully remove yellow plastic covering on Ag/AgCl electrode (as instructed) Place electrode in 15 mL falcon tube with enough NaCl solution to match volume in electrode cover and store upright until needed Prepare 50 mL 4 M KNO3 Add KNO3 to outer double junction cell, filling narrow tube + ~ 0.5 inches further Place electrode in small vial with enough KNO3 solution to cover the vycor tip Prepare 50 mL 0.01 M KI + 0.1 M KNO3 Cut a short piece (~ 3 in) of silver wire Place in KI/KNO3 solution Electrolyze the solution using the power supply The standard reduction potential for Ag/AgI is -0.15 V Oxidation occurs at the anode, which is connected to the red lead Electrolyze at low power (low current) until the wire appears coated Test your electrodes with a range of KI solutions The Ag/AgCl electrode slides inside of the KNO3 bridge solution (this is a double junction electrode) The Ag/AgI wire can be connected directly to a multimeter using alligator clips You will continue to connect your Ag wire to the red lead on the multimeter Protocol taken from Dr. Fox. Use this iodide ion selective electrode to create a calibration curve for [I-]. Additional Dialysis Analysis Jake did the following: Ran Titration Analysis on KI-Colloid dialysis Ran Bradford Analysis on KI-Colloid dialysis Description Titration Added 3mL 1M HNO3 and 0.5mL KI solution to 10mL DI H2O Added 2 mL AgNO3 and swirl to complete precipitation Added 200 μL Ferric alum indicator Titrate with your NH4SCN solution Ran Bradford Analysis on KI-Colloid dialysis As expected, the Bradford analysis held a constant protein concentration Lysozyme is too big to pass through the 3500 MWCO so it was constant on one side KI is not expected to react with lysozyme so protein concentration was not affected Data Above is the calibration curve for [I-] created using the iodide ion selective electrode. Notes This area is for any observations or conclusions that you would like to note. Use categories like tags. Change the "Course" category to the one corresponding to your course. The "Miscellaneous" tag can be used for particular experiments, as instructed by your professor. Please be sure to change or delete this tag as required so that the categories remain well organized.