a rookie question for hplc

[clint]

hi...i am doing analysis on carotene in 2 sample..
1 sample i use 2g but another one i just use 500mg only..
after submit to hplc analysis and get the peak area (mAU*s),
then can i compare peak like this:

sample 1 (2g) 1000.00000 mAU*s
sample 2 (500mg) 500.00000 mAU*s
i assume that sample 2 (4 x 500mg) (4 x 500 mAU*s = 2000 mAU*s)

so i will compare 1000 mAU*s (sample 1) with 2000 mAU*s (sample 2).
can i compare like above???

hope u understand what i mean...
any help is appreciate...

[Bruce Hamilton]

Sounds like an assignment, in which case refer to your notes.

If it isn't, then just dilute your sample 1, or reduce the injection size, so you also inject the equivalent amount to the 500mg sample size, and see what size peak appears.

Bruce Hamilton.

[clint]

thank bruce...i am doing my thesis
actually my sample is palm oil, sample i use alkaline saponification, and the 500mg sample i use lipase hydrolysis.. i wish to do anothe test but the lipase had out of stock already....
so i can juz ask theorically...

[Bruce Hamilton]

OK. You have to calculate to ensure that the mass injected is the same for each, and all other aspects of the analysis are identical, and you are within the linear range of the detector, then you can directly compare.

By that, I mean that you must ensure you know the dilutions for each sample. If you calculate that you injected 10 ul of 1 mg/ml of each, then the second sample contained 500/1000 of the first sample. You can also ratio the peaks, along with the actual amount injected, if they weren't the same

Bruce Hamilton

[clint]

thank again...bruce
that is very helpful...