By Anonymous on Tuesday, July 1, 2003 - 01:43 am:
Hi,
I'm absolutely rubbish at maths, so could anone help please?
I have the average peak height (in microamps) and an assayed percentage of two components, and I also have the average peak height of the two components in a sample. I have the masses of both standard and sample.
The two peaks' percentages add up to 100%, and I have the peak height/area too
How can I calculate the percentage of both components in the sample from the information I have from the standard and sample?
By Anonymous on Tuesday, July 1, 2003 - 02:41 am:
On the assumption that both peaks have the same response factor, then the percentage of each peak is just the height/area divided by the total height/area multiplied by 100. Eg if one peak is 120 units high, the other is 30units high, then the respective percentages are 80% (i.e. 120/(120+30) * 100) and 20%.
If your responses are different for the two peaks that then becomes Sample Ht (or Area)/Std Height (or Area) x Std Weight/Sample Weight (use same units for both) x Sample Dilution factor/Std Dilution factor (if diluted in same way, this will be 1) x 100% x Std purity (or assay percent) as a decimal. This gives a result of %w/w
Do this for each component and the total percentage should be around 100% (within the realms of analytical error)