USP Benzocaine Assay Result Help
Posted: Sat Aug 24, 2013 12:27 am
I'm trying to calculate the assay results for a Benzocaine raw material I ran. The results need to be 98.0%-102.0% Benzocaine.
The only formula on the USP method, is to calculate the quantity, in mg, of Benzocaine.
1000C(rU/rS)
Where C is the concentraion, in mg per ml, and rU and rS are the peak responses obtained from the Assay preparation and Standard preparation. 1000 is the dilution factor.
My calculation.
1000(0.0245mg/ml)(34822.20/35285.529)=24.18
My mass of the sample I weighed out was 23.9 mg.
So is my assay precentage found by (Sample Mass/Calculated Quantity)*100=(23.9/24.18)100=98.8%
Is it found by (Calculated Quantity/ Sample Mass)*100=(24.18/23.9)100=101.2%
Or is it some other formula I can't think of.
Thanks!
The only formula on the USP method, is to calculate the quantity, in mg, of Benzocaine.
1000C(rU/rS)
Where C is the concentraion, in mg per ml, and rU and rS are the peak responses obtained from the Assay preparation and Standard preparation. 1000 is the dilution factor.
My calculation.
1000(0.0245mg/ml)(34822.20/35285.529)=24.18
My mass of the sample I weighed out was 23.9 mg.
So is my assay precentage found by (Sample Mass/Calculated Quantity)*100=(23.9/24.18)100=98.8%
Is it found by (Calculated Quantity/ Sample Mass)*100=(24.18/23.9)100=101.2%
Or is it some other formula I can't think of.
Thanks!