Researcher

David Bulger

Objective

Verify the SAMS method using varying known concentrations of 2-phenylbutyric acid in DMSO against an internal standard of 1,2-dichloroethane.

Procedure

Calibrate pipets, make very dilute solution in 5-mL volumetric flask, make more concentrated solutions in 1-mL volumetric flask, prepare three solutions per concentration with CDCl3 and 1,2-dichloroethane for NMR, run NMR, and measure concentration using SAMS and internal standard.

Results

NMR

ONSC102-1A (0.024 M)
ONSC102-1B (0.024 M) ONSC102-1C (0.024 M) ONSC102-2A (0.25 M) ONSC102-2B (0.25 M) ONSC102-2C (0.25 M) ONSC102-3A (0.5 M) ONSC102-3B (0.5 M) ONSC102-3C (0.5 M) ONSC102-4A (1 M) ONSC102-4B (1 M) ONSC102-4C (1 M) ONSC102-5A (2 M) ONSC102-5B (2 M) ONSC102-5C (2 M) ONSC102-6A (3 M) ONSC102-6B (3 M) ONSC102-6C (3 M)
Raw JCAMP-DX file for ONSC102-1A
Raw JCAMP-DX file for ONSC102-1B Raw JCAMP-DX file for ONSC102-1C Raw JCAMP-DX file for ONSC102-2A
Raw JCAMP-DX file for ONSC102-2B Raw JCAMP-DX file for ONSC102-2C Raw JCAMP-DX file for ONSC102-3A
Raw JCAMP-DX file for ONSC102-3B Raw JCAMP-DX file for ONSC102-3C Raw JCAMP-DX file for ONSC102-4A Raw JCAMP-DX file for ONSC102-4B Raw JCAMP-DX file for ONSC102-4C Raw JCAMP-DX file for ONSC102-5A Raw JCAMP-DX file for ONSC102-5B Raw JCAMP-DX file for ONSC102-5C Raw JCAMP-DX file for ONSC102-6A Raw JCAMP-DX file for ONSC102-6B Raw JCAMP-DX file for ONSC102-6C

Pictures

ONSC102-1
ONSC102-2
ONSC102-3
ONSC102-4
ONSC102-5
ONSC102-6
ONSC102-7
ONSC102-8

Spreadsheets

[This is too confusing - just have one SAMS sheet and one sheet for the internal standard calculations JCB] Googledocs only allows 50 import functions per sheet. For SAMS alone, I can only fit a little over half of the calculations before it gives me an error message informing me that I am trying to import more than 50 functions.[Right - forgot about that limitation. I'll wait till you are done and comment later JCB]
ONSCExp102-1 This spreadsheet contains general calculations.
ONSC102-1 This spreadsheet contains SAMS for a variety of protons.
ONSC102-2 This spreadsheet contains internal standard calculations for a variety of protons.
ONSC102-3 This spreadsheet contains more SAMS for a variety of protons.
ONSC102-4 This spreadsheet contains more internal standard calculations for a variety of protons.
ONSC102-5 This spreadsheet contains summaries of data analysis.
ONSC-EXP102Hsheet The spreadsheet compares the error between the methyl and the methine protons

Discussion

ONSC102ExcelGraphs.xls
Screenshots of Graphs are Below:
ESAM.png
PESAM.png
EIS.png
PEIS.png
The average error for the SAMS method was found to average at approximately 20% error. The graphs for SAMS show a decreasing percent error as the concentration increases. This could be attributed to the NMR's ability to process both the large solvent peak and the small solute peak better when they have closer heights. Towards the higher concentrations, the graphs for SAMS show a slight increase in percent error. This could be attributed to the error in the density assumptions for the solute increasing in significance as the solute concentration increases. Although the Internal Standard method seems to average at approximately 45% error, the peak used in all the graphs was quite distorted with unclear beginning and ending. Therefore, the results for the Internal Standard error calculations are deemed unreliable.
methyl.pngmethine.png
[An analysis of error vs. concentration for each hydrogen selected for integration shows that the methyl group on 2-phenylbutanoic acid generated an average error of 8.4%, while the methine hydrogen generated an average error of 26%. There is no strong correlation of concentration with error, showing that errors related to volume expansion or contraction or estimate of solute density are not dominant. The difference in error between the methyl and methine hydrogens is likely related to relaxation time differences. JCB]

Conclusion

For 2-phenylbutyric acid in DMSO, the average percent error is approximately 20%.
[Actually the story gets more interesting if you plot the CH3 and CH measurements separately JCB]

Log

2009-05-28
11:40 Weighed three 1-dram vials:
Vial
Mass (g)
102A700-1
5.135 9
102B100
5.148 7
102C10
5.097 0
11:45 Pipetted 1 000 uL CDCl3 to 102A700, 100 uL DMSO to 102B100, and 10 uL 1,2-dichloroethane to 102C10
11:50 Weighed vials:
Vials
Mass (g)
102A700-1
6.820 9
102B100
5.303 6
102C10
5.111 8
12:00 Weighed vials:
Vials
Mass (g)
102A700-2
5.118 6
102B100
5.303 6
102C10
5.111 1
12:02 Pipetted 700 uL CDCl3 to 102A700-2, 100 uL DMSO to 102B100, and 10 uL 1,2-dichloroethane to 102C10
12:07 Weighed vials:
Vials
Mass (g)
102A700-2
6.268 6
102B100
5.466 8
102C10
5.124 2
12:11 Pipetted 100 uL DMSO to 102B100 and 10 uL 1,2-dichloroethane to 102C10
12:14 Weighed vials:
Vials
Mass (g)
102B100
5.617 8
102C10
5.137 8
12:23 Weighed 102B100 (5.618 4 g)
12:28 Added 100 uL DMSO to 102B100
12:29 Weighed 102B100 (5.777 6 g)
12:30 Added 100 uL DMSO to 102B100
12:31 Weighed 102B100 (5.936 9 g)
12:32 Reweighed 102B100 (5.937 3 g) and reweighed 102B100 again (5.936 1 g)
12:33 Added 100 uL DMSO to 102B100
12:34 Weighed 102B100 (6.096 1 g) using 10uL-100uL pipet
12:35 Added 100 uL DMSO to 102B100
12:36 Weighed 102B100 (6.207 2 g)
12:37 Reweighed 102B100 (6.199 3 g)
12:38 Added 100 uL DMSO to 102B100 and weighed (6.310 1 g)
12:39 Added 100 uL DMSO to 102B100 and weighed (6.419 3 g)
13:15 Weighed 5-mL volumetric flask (8.646 3 g)
13:32 Reweighed 5-mL volumetric flask (8.646 7 g)
13:35 Added 0.020 0 g 2-phenylbutyric acid to 5-mL volumetric flask
13:39 Weighed volumetric flask (8.666 7 g)
13:40 Added DMSO to just under 5-mL mark (solution 102-1)
13:45 Parafilmed and vortexed for 30 sec
13:47 Photo (ONSC102-1)
13:48 Room temperature is 21 degrees Celsius
13:49 Weighed 1-mL volumetric flask (15.605 1 g)
13:52 Began sonication (31 degrees Celsius) with copper wire support for 45 min
13:53 Added 0.041 1 g 2-phenylbutyric acid to 1-mL volumetric flask
13:58 Weighed 1-mL volumetric flask (15.646 2 g)
13:59 Added DMSO to just under 1-mL volumetric flask (solution 102-2)
14:01 Parafilmed and vortexed for 30 sec
14:03 Photo (ONSC102-2)
14:04 Began sonication for 30 min
15:21 Temperature in sonicator was 35 degrees Celsius
15:22 Photo (ONSC102-3)
15:23 Cleaned, dried, and labeled six NMR tubes (102-1A, 102-1B, 102-1C, 102-2A, 102-2B, 102-2C)
15:44 Labeled six 1-dram vials (102-1AP, 102-1BP, 102-1CP, 102-2AP, 102-2BP, 102-2CP)
15:47 Weighed vials:
Vial
Mass (g)
102-1AP
5.131 1
102-1BP
5.072 5
102-1CP
5.131 9
102-2AP
5.123 0
102-2BP
5.110 7
102-2CP
5.120 4
15:52 Added 700 uL CDCl3 to each vial and weighed:
Vial
Mass (g)
102-1AP
6.233 9
102-1BP
6.194 8
102-1CP
6.260 9
102-2AP
6.260 9
102-2BP
6.268 1
102-2CP
6.250 4
16:03 Added 10 uL 1,2-dichloroethane and weighed:
Vial
Mass (g)
102-1AP
6.243 7
102-1BP
6.204 9
102-1CP
6.270 3
102-2AP
6.270 4
102-2BP
6.260 3
102-2CP
6.278 7
16:12 Added 100 uL of solutions 102-1 and 102-2 to corresponding vials as follows:
Vial
Solution
102-1AP
102-1
102-1BP
102-1
102-1CP
102-1
102-2AP
102-2
102-2BP
102-2
102-2CP
102-2
pipetting into the solution followed by parafilming and vortexing for 30 sec
16:28 Transferred preparatory solutions to NMR tubes, capped amd parafilmed
16:40 Collected NMR's (ONSC102-1A, ONSC102-1B, ONSC102-1C, ONSC102-2A, ONSC102-2B, ONSC102-2C)
18:39 Cleaned 12 NMR tubes and 1-mL volumetric flask
19:12 Weighed 1-mL volumetric flask (15.630 7 g)
19:13 Added 0.082 1 g, 0.164 2 g, 0.328 4 g, and 0.492 6 g of 2-phenylbutyric acid onto four weighing sheets
19:27 Added 0.082 1 g to volumetric flask and weighed (15.712 2 g)
19:31 Added DMSO to just below 1-mL mark
19:35 Vortexed for 30 sec
19:35 Photo (ONSC102-4) - competely dissolved
19:36 Transferred to 1-dram vial (102-3) and parafilmed
19:38 Clean 1-mL volumetric flask with DMSO
19:39 Weighed 1-mL volumetric flask (15.603 3 g)
19:40 Added 0.164 2 g 2-phenylbutyric acid to 10mL volumetric flask and weighed (15.766 9 g)
19:47 Added DMSO to just below mark
19:50 Vortexed for 30 sec
19:51 Added DMSO to 1-mL mark and vortexed for 10 sec
19:52 Photo (ONSC102-5) - completely dissolved
19:53 Transferred solution to 1-dram vial (102-4) and parafimed
19:54 Cleaned 1-mL volumetric flask with DMSO
19:57 Weighed 1-mL volumetric flask (15.599 2 g)
20:01 Added 0.328 4 g 2-phenylbutryic acid to volumetric flask
20:02 Weighed volumetric flask (15.927 1 g)
20:03 Added DMSO to just below 1-mL mark
20:06 Vortexed for 1-min - completely dissolved
20:08 Added DMSO up to 1-mL mark
20:09 Weighed volumetric flask (16.658 1 g)
20:09 Photo (ONSC102-6)
20:10 Transferred solution to 1-dram vial (102-5) and parafilmed
20:13 Cleaned volumetric flask with DMSO
20:15 Weighed volumetric flask (15.594 2 g)
20:17 Added 0.492 6 g to volumetric flask and weighed (16.086 0 g)
20:25 Added DMSO to just below 1-mL mark
20:29 Vortexed for 1-min - completely dissolved and expanded to 1-mL mark
20:31 Photo (ONSC102-7)
20:32 Weighed volumetric flask (16.679 5 g)
20:33 Transferred solution to 1-dram vial (102-6) and parafilmed
20:35 Photo (ONSC102-8)
20:35 Weighed vials:
Vials
Mass (g)
102-3AP
5.098 6
102-3BP
5.124 5
102-3CP
5.070 2
102-4AP
5.104 4
102-4BP
5.105 4
102-4CP
5.089 2
102-5AP
5.113 0
102-5BP
5.123 5
102-5CP
5.101 0
102-6AP
5.079 1
102-6BP
5.082 8
102-6CP
5.098 9
20:46 Added 700 uL CDCl3 to each vial and weighed:
Vials
Mass (g)
102-3AP
6.203 6
102-3BP
6.254 9
102-3CP
6.326 8
102-4AP
6.231 1
102-4BP
6.239 0
102-4CP
6.210 2
102-5AP
6.246 5
102-5BP
6.258 0
102-5CP
6.224 4
102-6AP
6.228 4
102-6BP
6.222 8
102-6CP
6.217 5
20:58 Added 10 uL of 1,2-dichloroethane to each vial and weighed:
Vials
Mass (g)
102-3AP
6.216 3
102-3BP
6.265 2
102-3CP
6.229 5
102-4AP
6.242 0
102-4BP
6.251 2
102-4CP
6.221 7
102-5AP
6.259 3
102-5BP
6.269 0
102-5CP
6.234 4
102-6AP
6.239 0
102-6BP
6.235 5
102-6CP
6.228 3
21.13 Added 100 uL of solutions (102-3 through 102-6) to corresponding preparatory vials
21:29 Tricherated solutions, transferred solutions to corresponding NMR tubes, and parafilmed
21:53 Vortexed NMR tubes for 10 sec
21:55 Collected NMR's (ONSC102-3A, ONSC102-3B, ONSC102-3C, ONSC102-4A, ONSC102-4B, ONSC102-4C, ONSC102-5A, ONSC102-5B, ONSC102-5C, ONSC102-6A, ONSC102-6B, ONSC102-6C)