Docstoc

nmr

Document Sample
nmr Powered By Docstoc
					NMR

Objective:
The purpose of this lab is to learn how to obtain NMR spectra from various standard samples. 1H and 13C analysis will be
done to provide structures for an unknown sample.

Procedure:
    1. NMR tubes were created for Palmitic Acid, Stearic Acid, Vegetable Oil and Olive Oil with CDCl3 as the solvent.
    2. The NMR was prepared to run analysis on both 1H and 13C for each sample.
    3. Spectrum was obtained for each sample and analysis was done to determine structure for each sample.

Data:
 Olive Oil                                 Palmitic Acid
 PPM                   Int                 PPM                   Int
                  5          7.97                          0.1         1.88
                  6          1.68                          0.9         6.55
                 6.6         0.07                          1.3         52.8
                 7.5          0.1                          2.4         4.36
                  8           0.4                          7.5           1
                 9.1         0.68          Chain Length=           66.59
              11.1           4.79
 Chain Length=           15.69


 Vegetable Oil                             Stearic Acid
 PPM                   Int                 PPM                   Int
                 0.9           1                           0.1         1.86
                  1          0.33                          0.9         2.63
                 1.3          6.2                          1.3         22.2
                 1.6         0.74                          2.4         1.68
                  2          1.24                          7.5           1
                 2.3         0.76          Chain Length=           29.37
                 2.8         0.51
                 4.1         0.25
                 4.3         0.24
                 5.3         1.25
 Chain Length=           12.52

Conclusions:
This experiment seemed fairly unsuccessful. Our integration values were real low that normalization on them would have
produced very small chain lengths. While the integrals that we received provided chain lengths that seem reasonable.
Olive oil has a chain length of 17.7, while ours was 15.69 which don’t seem that too far off. Vegetable is unknown in chain
length and we received a value of 12.52. The acids on the hand had very drastic differences and each had a high integral
total for 1.3ppm position. Our olive oil 1H seemed rather skeptical as its peaks started t 4.6ppm which seems highly
unlikely. As for the 13C analysis the oils have very good resolution while the acids had a lot of feedback and huge baseline
thickness that peaks were not able to be picked out in some areas. Some sources of error for this lab would include our
preparation of NMR tubes and possible getting better locks on the tube when injected into the instrument.

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:39
posted:8/18/2011
language:English
pages:2