20. Specific Activity (SA) of molecules C SA = 62.4 mCi/mmol C C C C C C [1- 14 C] compound SA = 62.4 mCi/mmol C C C C C C [U- 14 C] compound SA= 6 x 62.4 = 374.4 mCi/mmol
21. Decreasing the Specific Activity (SA) Adjusted SA = 62.4/6 = 10.4 mCi/mmol Add 5 equivalents of inactive compound C C C C C C [1- 14 C] compound SA = 62.4 mCi/mmol C C C C C C
40. Distribution of solute molecules (x) in aqueous and in frozen aqueous solutions – molecular clustering effect on slow freezing
41. Stability of [ 14 C]-Compound 100% 80% 90% Radiochemical purity 4 8 12 20 15 Time (weeks)
42. Effect of Specific Activity Decomposition of [ 14 C]-Compound at 20°C 100% 30% 90% 60% 20 55 120 Specific activities in mCi/mmol 7 Time (days) Radiochemical purity
43. Effect of Temperature Stability of [ 14 C]-Compound 100% 70% 90% 80% -80º -20º 20º 6 3 1 Time (weeks) Radiochemical purity
44. Effect of Free Radical Scavengers Decomposition of [ 14 C]-Compound at 20ºC 100% 90% 80% 70% 4 2 3 1 Time (months) Radiochemical purity + 3% ethanol Aqueous solution