Objectives
 Calculate the amount of AgNO_{3} 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 H_{2}O to test for Ag^{+} leaching with a silver ion selective electrode.
Calculations
 Two sample calculations are given as examples. The final [Ag^{+}] in 50mL solutions of LB media was calculated as follows:
1 μM Ag^{+} in 50 mL of LB media
(0.0105 M Ag^{+}) × V_{1} = (1×10^{6} M) × (50 mL)
V_{1} = 0.00476 mL of 0.0105 M AgNO_{3}
10 μM Ag^{+} in 50 mL of LB media
(0.1 M Ag^{+}) × V_{1} = (10×10^{6} M) × (50 mL)
V_{1} = 0.005 mL of 0.1 M AgNO_{3}
 AgNO_{3} solutions made on 2013/02/05 and 2013/02/13 were added to the LB media solutions in the following amounts:
Final [Ag^{+}]
 Volume of AgNO_{3} 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 AgNO_{3} added to the LB media, the same volume of LB media was first removed from the flask to maintain the final concentration of Ag^{+}.
ISE Study of PLA2002D + 5 wt% 100AgLMT
 Calculations
 To determine maximum [Ag^{+}] possible, assume that all Ag^{+} leaches out of solution.
 The solution contained 50 mL pure H_{2}O 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 ÷ 0.051 L = 8.76 × 10^{7} M or 0.876 μM
 Protocol
 Pour 50 mL pure H_{2}O into a clean, dry 250mL Erlenmeyer flask and add 1 mL of 5 M KNO_{3}.
 Measure the conductivity of the solution with the ISE.
 Place a single 0.5 g piece of film into the flask, swirl, and measure the conductivity.
 Wait 30 min, then measure the conductivity again.
 Repeat the above step 5 more times.
