Katie Rexroth
April 15, 2013
HPLC/LC-MS Lab Report
Introduction
HPLC stands for high pressure liquid chromatography. It is commonly used for water based samples. The
mobile phase is liquid and the stationary phase is either liquid or solid. The LC-MS works in the same
way as the LC-MS however it has a mass spec detector that is used to analyze the sample.
Purpose
The purpose of this lab was to create a calibration curve of caffeine so that we could use it to determine
the levels of caffeine in both caffeinated and decaffeinated tea samples. We could then compare the
calibration curves from both the HPLC and the LC-MS to see which one was better.
Procedure
We prepared our samples from a 1000 ppm stock solution of caffeine in distilled water. We diluted it
down to 50, 40, 30, 20, and 10 ppm. We followed the SOP for the HPLC which was very straight forward.
The LC-MS was not in operation at the time of this lab so we weren’t able to collect any data from it.
Data
*All HPLC chromatograms are in lab notebook.
Concentration 50
(ppm)
Area
1173275
40
30
20
10
971732
750870
525784
469527
Caffeinated
Tea
279437
HPLC Caffeine Concentration Curve
1.510 0 6
y=18,534x+222,204
Area
1000000
500000
0
0
20
40
60
Concentration (ppm)
Calculations
Caffeinated Tea
279437=18534x+222204
X= 3.088 ppm
Conclusions
Our calibration curve for the HPLC was actually pretty good. From it we determined the Rutter’s Tea to
have a concentration of 3.088 ppm. The HPLC was pretty easy to use. We didn’t have any problems
running it. The only thing we could’ve done was messed with the percentage of methanol and degassed
water to have better resolution of our peaks. On our tea sample especially, the peaks were not very well
dissolved. Unfortunately the LC-MS wasn’t working properly so we weren’t able to use it so we had
nothing to compare the performance of the HPLC to.