User:Karlena L. Brown/Notebook/PVOH Research/2012/10/09

OBJECTIVES

• Remake CuSO₄ standard solutions for atomic absorption
• Use the ion selective electrode to measure all CuSO₄ solutions established
• Prepare PVOH samples for DSC testing and analysis
• Collect all data and experimental results from DSC testing and analysis

Ion Selective Electrode Procedures

1. Plug the Na⁺ electrode into the SympHony meter and turn on instrument
2. Then press the arrows until ISE (ion selective electrode) and mV (millivolts) appear on the screen
3. Remove the electrode from the storage solution
4. Rinse the electrode with distilled H₂O and thoroughly dry it with a KimWipe
5. Place the electrode directly into the 1ppm CuSO₄ solution for analysis
6. Let the solution and electrode equilibrate for a set period of time (between 2-5 minutes) and then press measure
7. Once the measurement is finalized, record the value observed
8. Create a standard ISE calibration curve

REPEAT ABOVE PROCEDURES FOR ALL CuSO₄ STANDARD SOLUTIONS:2 ppm, 5 ppm, 10 ppm, AND 15 ppm

REPEAT ABOVE PROCEDURES FOR ALL Na₂SO₄ STANDARD SOLUTIONS:1 ppm, 2 ppm, 5 ppm, 10 ppm, 15 ppm, AND 20 ppm

REPEAT PROCEDURES FOR INTERVAL AQUEOUS FILTRATE CuSO₄ EXCHANGED CLAY SOLUTIONS: 7.4 ppm AND 10 ppm

Ion Selective Electrode Standard Dilutions & Calculations

Na₂SO₄ Dilution Standards

5mL 1 ppm Na2SO4 requires:
 (1000 ppm Na2SO4)V1 = (1 ppm Na2SO4)(5mL)
   V1 = 0.005mL

5mL 5 ppm Na2SO4 requires:
 (1000 ppm Na2SO4)V1 = (5 ppm Na2SO4)(5mL)
   V1 = 0.025mL

5mL 10 ppm Na2SO4 requires:
 (1000 ppm Na2SO4)V1 = (10 ppm Na2SO4)(5mL)
   V1 = 0.05mL

5mL 15 ppm Na2SO4 requires:
 (1000ppm Na2SO4)V1 = (15 ppm Na2SO4)(5mL)
   V1 = 0.075mL

5mL 20 ppm Na2SO4 requires:
 (1000 ppm Na2SO4)V1 = (20 ppm Na2SO4)(5mL)
   V1 = 0.100mL

CuSO₄ Dilution Standards

12mL 1 ppm CuSO4 requires:
 (20ppm CuSO4)V1 = (1ppm CuSO4)(12mL)
   V1 = 0.6mL

12mL 2 ppm CuSO4 requires:
 (20ppm CuSO4)V1 = (2ppm CuSO4)(12mL)
   V1 = 1.2mL

12mL 5 ppm CuSO4 requires:
 (20ppm CuSO4)V1 = (5ppm CuSO4)(12mL)
   V1 = 3mL

12mL 10 ppm CuSO4 requires:
 (20ppm CuSO4)V1 = (10ppm CuSO4)(12mL)
   V1 = 6mL

12mL 15 ppm CuSO4 requires:
 (20ppm CuSO4)V1 = (15ppm CuSO4)(12mL)
   V1 = 9mL

Ion Selective Electrode Sample Preparations & Results

Before collecting sample measurements from the ion selective electrode instrument:

• Upon testing the pH of the standard solutions, it was concluded that the pH was too low (~7.8)
• Therefore, pH adjustments made for each solution: 0.1mL of ionic strength adjuster (4M pH adjuster containing NaOH) + 3mL of sample solution
• The ionic strength pH adjuster adjusted the pH of the solutions between 8 and 10
• The solvent used to dilute each solution was distilled H₂O

ISE and pH measurements

DSC Sample Preparation

RECALL DSC PROCEDURES FROM 9/17/12

Notes

• The 1 ppm Na⁺ solution provided an ISE value outside of the expected calibration curve due to the > 1 ppm LOD (limit of detection)
• Recommendation: Make standards larger than 25 ppm Na⁺ to create more accurate calibration curve
• The ISE values of the CuSO₄ solutions are meaningless as they were obtained with a sodium electrode