# User:Melissa Novy/Notebook/CHEM-572/2013/02/20

(Difference between revisions)
 Revision as of 21:28, 27 February 2013 (view source) (→ISE Study of PLA2002D + 5 wt% 100Ag-LMT)← Previous diff Revision as of 11:11, 18 March 2013 (view source) (→ISE Study of PLA2002D + 5 wt% 100Ag-LMT)Next diff → Line 63: Line 63: ** The solution contained 50 mL pure H2O and 1 mL [[User:Melissa_Novy/Notebook/CHEM-572/2013/02/12|ionic strength adjuster]].  The recommended ratio of solution to ionic strength adjuster is 50 mL to 1 mL.  Then, 0.50 g of film was added to the solution. ** The solution contained 50 mL pure H2O and 1 mL [[User:Melissa_Novy/Notebook/CHEM-572/2013/02/12|ionic strength adjuster]].  The recommended ratio of solution to ionic strength adjuster is 50 mL to 1 mL.  Then, 0.50 g of film was added to the solution. - '''(4.47 × 10-8mol Ag+0 ÷ 0.051 L = 8.76 × 10-7 M or 0.876 μM''' + '''(4.47 × 10-8 mol Ag+) ÷ 0.051 L = 8.76 × 10-7 M or 0.876 μM'''

## Revision as of 11:11, 18 March 2013

Search this Project

Customize your entry pages

## Objectives

• Calculate the amount of AgNO3 to add to LB media solutions for desired final [Ag+].
• Remove PLA films, made on 2013/02/19, from glass molds.
• Soak PLA films in pure H2O to test for Ag+ leaching with a silver ion selective electrode.
• Run X-ray on 100Ag-LMT.
• Harvest DH5α-T1 cells for Ag+ cell growth inhibition studies.

## DH5α-T1 Cell Harvesting

• Five cell starter cultures, made on 2013/02/19 were obtained and their absorbance at 600 nm was recorded.
• Please refer to Keyun Wang's entry for the absorbance data and the protocol to pellet the cells.

## Calculations

• Two sample calculations are given as examples. The final [Ag+] in 50-mL solutions of LB media was calculated as follows:
```  1 μM Ag+ in 50 mL of LB media
(0.0105 M Ag+) × V1 = (1×10-6 M) × (50 mL)
V1 = 0.00476 mL of 0.0105 M AgNO3
```
```  10 μM Ag+ in 50 mL of LB media
(0.1 M Ag+) × V1 = (10×10-6 M) × (50 mL)
V1 = 0.005 mL of 0.1 M AgNO3
```
• AgNO3 solutions made on 2013/02/05 and 2013/02/13 will be added to the LB media solutions in the following amounts:
 Final [Ag+] Volume of AgNO3 Solution Added 1 μM 4.76 μL of 0.0105 M 10 μM 5.00 μL of 0.1 M 100 μM 50.0 μL of 0.1 M 1 mM 500 μL of 0.1 M 10 mM 5000 μL of 0.1 M
• Note that for each volume of AgNO3 added to the LB media, the same volume of LB media will first be removed from the flask to maintain the final concentration of Ag+.

## ISE Study of PLA2002D + 5 wt% 100Ag-LMT

• Calculations
• To determine maximum [Ag+] possible, assume that all Ag+ leaches out of solution.
• The solution contained 50 mL pure H2O and 1 mL ionic strength adjuster. The recommended ratio of solution to ionic strength adjuster is 50 mL to 1 mL. Then, 0.50 g of film was added to the solution.
```  (4.47 × 10-8 mol Ag+) ÷ 0.051 L = 8.76 × 10-7 M or 0.876 μM
```

• Protocol
1. Pour 50 mL pure H2O into a clean, dry 250-mL Erlenmeyer flask and add 1 mL of 5 M KNO3.
2. Measure the conductivity of the solution with the ISE.
3. Place a single 0.5 g piece of film into the flask, swirl, and measure the conductivity.
4. Wait 30 min, then measure the conductivity again.
5. Repeat the above step 5 more times.

 Time [min] Conductivity [mV] [Ag+] [M] mol Ag+ [umol] 0 384.9 0.000204407 10.42474353 30 379.9 0.000163526 8.339821664 60 372.5 0.000117534 5.994210823 90 367.2 9.27767E-05 4.731609351 120 366.8 9.11352E-05 4.647893756