[manypostcards]

Hi,

I'm currently writing up an HPLC lab report. One objective is to find the concentration of caffeine in Mountain Dew. The professor ran the sample himself (while we weren't there) and e-mailed us the results which contained peak area values for caffeine, potassium sorbate, and sodium benzoate in Mountain Dew. We prepared the samples ourselves, so I have the by-weight values in grams of the Mountain Dew and mobile phase in my sample. Is this enough information to determine the conc. of caffeine in my soft drink sample?

After doing a search on this forum and the internet I couldn't figure it out although I'm starting to get the gist. However it seems that in any calculation I need a known concentration, namely for both a calibration curve or response factor calculation.

I'll note that I also have the peak area data of other students' samples of various caffeine-containing beverages.


Much thanks,
mp

[Arkcon]

Yes, you will have to have an area for a standard:   that's a sample of pure caffeine of known concentration.  Can you look at all the data you've been given to begin to work that out?  Maybe build a table, in Excel.

[manypostcards]

Hi, thanks for the reply. Unfortunately I do not have such data. I e-mailed my TA; hopefully she can shed light on the situation.