EXP329

=Researcher= Matthew McBride =Objective= To determine the extinction coefficient of trans-dibenzalacetone in ethanol =Procedure= Dissolve a known amount of trans-dibenzalacetone in ethanol and calculate the extinction coefficient using UV/Vis Spectroscopy and Beer's law. =Results= [|UV/Vis Spectrum] λ max: 328 nm Absorption units at λ max (A): 0.015550 Pathlength (L): 1 cm Concentration (c): 9.3046e-8 M Calculated extinction coefficient (ε) using Beer's Law (A=εLc): 167121
 * Solution A_100,000**

[|UV/Vis Spectrum] λ max: 329 nm Absorption units at λ max (A): 0.120824 Pathlength (L): 1 cm Concentration (c): 9.3046e-7 M Calculated extinction coefficient (ε) using Beer's Law (A=εLc): 129854
 * Solution A_10,000**

[|UV/Vis Spectrum] λ max: 330 nm Absorption units at λ max (A): 0.580883 Pathlength (L): 1 cm Concentration (c): 9.3046e-7 M Calculated extinction coefficient (ε) using Beer's Law (A=εLc): 624296 =Discussion= Calculated values are not consistant and high =Conclusion= No reliable extinction coefficient could be determined. =Log=
 * Solution B_10,000**

2012-07-31
16:23 Added 0.0109 g of trans-dibenzalacetone (Product 284A from UCEXP284) to a 5-dram snap cap vial. 16:28 Added approximately 2-3 mL of ethanol to the vial and dissolved the crystals. The solution was then transferred to a 5 mL volumetric flask and filled with ethanol. This was the stock solution (Solution A) with a concentration of 0.0093046M. 16:30 50 µL of Solution A was added to a 5 mL volumetric flask and filled with ethanol to create Solution A_100dilution. 16:33 50 µL of Solution A_100dilution was added to a 5 mL volumetric flask and filled with ethanol to create Solution A_10,000dilution. 16:40 1 mL of Solution A_10,000dilution was added to a 10 mL volumetric flask and filled with ethanol to create Solution A_100,000dilution. 3 mL of this solution was added to a cuvette with a 1 cm pathlength and analyzed by UV/Vis spectroscopy. The file of this spectrum was saved as ONSEXP329A_100,000dilution. The absorption units of this spectrum was 0.01. 17:00 3 mL of the Solution A_10,000 was added to a cuvette and analyzed by UV/Vis spectroscopy. The file of the spectrum was saved as ONSEXP329A_10,000. The absorption units of this spectrum was around 0.12.

2012-08-01
16:03 Inverted Solution A several times to throughly mix the solution. Added 50 µL of Solution A to a 5 mL volumetric flask and filled with ethanol. This is Solution B_100dilution. The solution was inverted several times to throughly mix. 16:11 Added 50 µL of Solution B_100dilution to a 5 mL flask and filled with ethanol. This is Solution B_10,000dilution. The solution was inverted several times to throughly mix. 3 mL of Solution B_10,000dilution was added to a cuvette with a 1 cm pathlength and analyzed by UV/Vis spectroscopy. The file of the spectrum was saved as ONSEXP329B_10,000dilution.