Researcher

Hieu Nguyen

Objective

To determine solubility of phenanthrene-9-carboxaldehydein chloroform using SAMS HNMR method.

Procedure

Add the solute to a 1 dram vial (with screw cap) with the solvent and allow the solution to shake on the 25°C shake flask apparatus. Measure solubility using SAMS HNMR method.

Results

The sample cannot be used in SAMS HNMR technique because there are some crystals in the sample that interfere with HNMR. Therefore, no result is obtained.

Discussion

The crystals appear in the sample due to the cooling down of temperature in the laboratory [this is not the reason you had crystals form JCB]. A sample can only be used in HNMR if the solution does not contain any kinds of crystal even a very small amount.

Conclusion

The HNMR method is failed to use because the NMR was not performed immediately for both two samples. Therefore, the chloroform evaporation changed the concentration of the solution that will make an inaccurate result. Specifically, some of the crystals was transferred from the flask into the tube that makes the second NMR tube was a not homogeneous solution anymore.

Log

2012-11-05

11:36--Used the analytical balance to weigh a 1 dram empty vial (with the screw cap). Record exactly its mass in the notebook.
11:43--Transferred about 0.6g of phenanthrene-9-carboxaldehyde into the vial by using the analytical balance to check the mass of the compound added
11:46--Added about 1mL of chloroform to the small vial using 10 mL graduated cylinder.
11:48--Shook the vial several times.
11:52--Labeled the vial as vial A using a marked pen.
11:53--Used the parafilm cap to seal the vial.
11:54--Used the thermometer to check the temperature of the control temperature bath. Observed that the temperature is 25 Celsius Degree.
11:56--Attached the vial to the control temperature bath using duct tape.
11:57--Turned on the control temperature bath and set the power of vortex at level 3.

2012-11-07

11:14--Turned the temperature control bath off and used the thermometer to check the temperature of the TCB. Observed that the temperature in the bath is 25 Celsius Degree.
11:15--Removed the vial from the shake flask apparatus. Observed that there is a solid layer at the top of the vial and the supernatant is at the bottom.
11:16--Took picture 1
11:17--Placed the vial inside the hood.
11:18--Removed the parafilm and screw cap.
11:19--Used the glass pasteur pipet to transfer a small amount (2-3 drops) of the supernatant to the inner NMR tube .
11:20--Gently shook it to make sure all of the supernatant is at the bottom of the NMR tube.
11:24--Used another pipet to trasnfer approximately 0.75 mL (about a half drop) of Deuterium Oxide to the outer NMR tube.
11:25--Put the inner tube inside the outer tube.
11:26--Took picture 2.
11:28--Sealed the vial with the parafilm cap.
11:29--Attach the vial to the shake flask apparatus using duct tape.
11:30--Turned the temperature control bath on at 25 Celsius Degree and set the power of vortex at level 3.

2012-11-11

11:08--Turned the temperature control bath off.
11:09--Used the thermometer to check the temperature of the temperature control bath. Observed that the temperature decreased to 24 Celsius Degree.
11:10--Took the small vial out of the shake flask apparatus.
11:12--Observed that there is crystal at the top of of the vial (totally cover the open side of the vial)
11:14--Transferred 2-3 drops of the supernatant to the inner NMR tube.
11:15--Gently shook the tube to make the liquid comes to the bottom.