Chromatography Forum

I have tried several times to get Empower and my spreadsheet to give matching amounts for "Amount" of related substance, and despite suggestions from here its still not working. Can anyone see what I'm doing wrong here, surely it shouldn't be this hard?

Weight of Standard = 5.0mg.
Purity of Standard = 99.2%
Diluted to 100mls for stock standard.
4mls of stock standard diluted to 100mls for working standard (this is the standard injected).

Weight of Sample = 2000mg.
Diluted to 50mls, then 5mls of this into 50mls for final sample solution (this is the sample injected).
Injection volume of standards/samples = 5 microlitres.

Formula in method for % (w/w)=
Weight Adjusted Sample/Weight Adjusted Bracketing Standard x (Purity/100).

Empower:
Average by (Amount or Concentration?)
I put my standard conc in component editor and my sampleweight in the sample lines (2000mg). I do clear cal, cal and quantitate and im getting nothing like what Excel is returning.

Sample Set:

S01 Standard
U01 Sample
S02 Standard
Clear Calibration
Calibrate
Quantitate

Can anyone help please?

Can you do a screenshot of the entries in the Samples window and the entries under Amounts?

Standard concentration should be determined by weight, initial volume, standard purity and dilution factor.

Same for sample (weight, initial volume and dilution factor).

Thanks for reply i should be able to post screens next week.
For std conc i took into account the putity weight and volume but for samples i weight out 2000mg into 50mls then 5mls into 50 so would my dilution value be 5/50 or 2000/50 * 5/50?

Its the little things that could be tripping me up.

to figure out how much whatever was in your 2000mg sample, your dilution factor is the reciprocal of your actual dilutions, 50*50/5, or 500.

Thanks for reply i should be able to post screens next week.
For std conc i took into account the putity weight and volume but for samples i weight out 2000mg into 50mls then 5mls into 50 so would my dilution value be 5/50 or 2000/50 * 5/50?

Its the little things that could be tripping me up.

Your dilution factor is 10 (50/5 - final volume divided with the initial-transferred volume). A dilution factor does not tell you what the initial volume is.