Repeat of JennyHale-3: Measuring the solubility of benzotriazole-5-carboxylic acid; 8-bromo-octanoic acid; 4-dimethylaminocinnamaldehyde and 2-(4-hydroxyphenyl)azobenzoic acid in ethanol and methanol.

This experiment seeks to repaet JennyHale-3 to see how the solubilities were affected by incomplete mixing in the previous attempt. THF experiment will be carried out soon. The bottle lids have become stuck again.

Method

12 2 mL screw cap vials were taken and labelled with their planned contents. 12 microcentrifuge tubes ("Eppendorfs") were taken, labelled with their planned contents and the masses recorded. Saturated solutions for benzotriazole-5-carboxylic acid; 4-dimethylaminocinnamaldehyde and 2-(4-hydroxyphenyl)azobenzoic acid were prepared by adding solid to 750 µL ethanol and methanol, and vortexing in short intervals for at least 3 minutes per sample until solutions were saturated. It was not possible to prepare saturated solutions of 8-bromo-octanoic acid as it was used up mid experiment. The full sample preparation can be seen in the log. The solutions were centrifuged on an Eppendorf 5415D centrifuge at 13 200 rpm/16 100 rcf for 1 minute.
500 µL of each supernatant was added to its respective Eppendorf and the solutions dried by speedvac, initially for 3 hours. the samples were removed and the masses of the tubes recorded. the tubes were returned tpo the speedvac to dry to constant mass.
The details of the solubility results can be found in spreadsheet JennyHale-11.

Results

The results of this experiment show mixed correlation to JennyHale-3. Whilst some solubilities have increased as expected to fit the model, others have decreased or stayed the same. The experiment will need to be run again to see whether the results are confirmed for a third time. Newly calculated solubilities and comparison notes are found in the spreadsheet.

Log

Monday 26.01.09 GMT

Pre 10.41 - Prepared eppendorfs and screw cap vials, pipetted 750 µL ethanol and methanol into vials accordingly.
10.41 - 4 narrow spatula scoops of benzotriazole-5-carboxylic acid added to ethanol. Vortexed for 1 minute in 10 second intervals. Solution apparently saturated.
10.43 - Vortexed the benzotriazole-5-carboxylic acid in ethanol solution for 2 minutes in 10 second intervals. Solution saturated.
10.45 - 4 narrow spatula scoops of benzotriazole-5-carboxylic acid added to methanol. Vortexed for 1 minute in 10 second intervals. Solution apparently saturated.
10.47 - Vortexed the benzotriazole-5-carboxylic acid in methanol solution for 2 minutes in 10 second intervals. Solution saturated.
10.51 - 4 Narrow spatula scoops of 8-bromo-octanoic acid added to ethanol. Vortexed for 10 seconds.
10.52 - 4 Narrow spatula scoops of 8-bromo-octanoic acid added to ethanol. Vortexed for 10 seconds.
10.53 - 4 Narrow spatula scoops of 8-bromo-octanoic acid added to ethanol. Vortexed for 30 seconds in 10 second intervals.
10.56 - 4 Narrow spatula scoops of 8-bromo-octanoic acid added to ethanol. Vortexed for 30 seconds in 10 second intervals.
10.58 - 4 Narrow spatula scoops of 8-bromo-octanoic acid added to ethanol. Vortexed for 30 seconds in 10 second intervals.
10.59 - 8 Narrow spatula scoops of 8-bromo-octanoic acid added to methanol. Dropped sample of 8-bromo-octanoic acid in ethanol and spilt it (lid off as was about to add solid). Vortexed 8-bromo-octanoic acid in methanol for 20 seconds in 10 second intervals.
11.02 - 4 Narrow spatula scoops of 8-bromo-octanoic acid added to methanol. Vortexed for 10 seconds.
11.04 - 6 Narrow spatula scoops of 8-bromo-octanoic acid added to methanol. Vortexed for 20 seconds in 10 second intervals.
11.07 - 4 Narrow spatula scoops of 8-bromo-octanoic acid added to methanol. Vortexed for 30 seconds in 10 second intervals.
11.10 - All remaining 8-bromo-octanoic acid added to methanol. Vortexed for 20 seconds in 10 second intervals. Solution not saturated. Abandoned solution.
11.12 - 4 Narrow spatula scoops of 4-dimethylaminocinnamaldehyde added to ethanol. Vortexed for 3 minutes in 10 second intervals. Solution saturated.
11.16 - 4 Narrow spatula scoops of 4-dimethylaminocinnamaldehyde added to methanol. Vortexed for 3 minutes in 10 second intervals. Solution saturated.
11.20 - 4 Narrow spatula scoops of 2-(4-hydroxyphenyl)azobenzoic acid added to ethanol. Vortexed for 3 minutes in 10 second intervals. Solution saturated.
11.25 - 4 Narrow spatula scoops of 2-(4-hydroxyphenyl)azobenzoic acid added to methanol. Vortexed for 20 seconds in 10 second intervals. Very viscous gloop produced with consistency and appearance of pureed carrot.
11.27 - started again with the 2-(4-hydroxyphenyl)azobenzoic acid in methanol. 4 Narrow spatula scoops of 2-(4-hydroxyphenyl)azobenzoic acid added to methanol. Vortexed for 1 minute in 10 second intervals to produce another thick solution with appearance of watered down pureed carrot.
11.32 - Checked all solutions remained saturated.
11.33 - Centrifuged solutions for 1 minute.
11.36 - Transferred 500 µL supernatant to respectively labelled eppendorfs.
11.42 - Started speedvac having transferred samples.
14.55 - removed samples from speedvac, recorded masses and returned to speedvac.