User:Monika Gasiorek/Notebook/CHEM-571 2014F/2014/10/21
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October 21, 2014Primary Experiment #1 - KI Titrations500 mL of 10 mM NH4SCN was prepared using a volumetric flask.
NH4SCN Standardization 3 mL of 1 M HCl, 2 mL of AgNO3, and 10 mL of water were titrated with the prepared NH4 solution in the presence of 400 μL of ferric alum indicator.
AgNO3+NH4SCN→AgSCN(s)+NH4NO3
[NH4SCN]=9.63 mM KI Titrations The standardized NH4SCN titrant was used to titrate 500 μL* samples of each of the dialysis wells from Primary Experiment #1. The same procedure was followed as was done for KI standardization on October 8, 2014, with the exception of KI sample size (500 μL instead of 1 mL). Additionally, 400 μL of indicator were used instead of 200 μL. *NOTE: The 50 mM KI titration was initially done incorrectly and the remainder of the sample was used for trial 2. There were only 350 μL left at this point. NOTE: These values are inconsistent with both the starting conditions and expected results. Each sample will be re-tested for KI concentration using the Iodide Ion Selective Electrode currently being assembled/tested. Primary Experiment #2 - Work-UpFluorescence/UV Analysis Fluorescence was run on DI water and 30:1 [Au]:[Protein] colloid to determine if fluorescence was necessary for the colloid vs. CaCl2 dialysis samples. As demonstrated below, no fluorescence was detected for the colloid (after determining no protein was present in the cuvette with blank water samples), so no fluorescence or UV-VIS analysis was necessary for these samples. Ca2+ ISE Calcium ISE was run on all ten dialysis samples. The samples were transferred to vials that the probe could be placed in. The results are below:
Iodide Ion Selective Electrode PreparationThree solutions were prepared:
This will be continued tomorrow.
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