Accuracy samples preparation in method validation.?

[surinzp]

Hi all,

I have to perform the recovery experiment for a related impurities HPLC method. I have to cover the range from LOQ to 150% of my impurity spec limit. The main analyte sample prep is 1.5g in 100mL and my impurity spec is 0.5%.

Can anyone tell me how to prepare the spiked sample for recovery experiment. How to calculate the Impurity spiking levels and what about the main analyte sample weight in spiked solutions?

Thanks

[Laurent]

Hello,

Don't you have any internal SOP to use ?
What is your LOQ ?

Personnaly i'll proceed so :

1/ Make a stock solution of the impurity (112.5 mg/L)

2/ Make a calibration curve of 5 points with 100ml graduated vials
Can be 10 points if your LOQ is very low (less than 5% stock solution concentration)

Vial 1 : 1,5g of analyte sample in 100ml of stock solution
Vial 2 : 1,5g of analyte sample in 75ml of stock solution
Vial 3 : 1,5g of analyte sample in 50ml of stock solution
vial 4 : 1,5g of analyte sample in 25ml of stock solution
vial 5 : 1,5g of analyte sample in X ml of stock solution

X is calculated by dilution of the stock solution in 100ml to be your LOQ

Of course complete with dilution solvent to go to 100ml jauge of the vials.

Hope this can help you.

[surinzp]

Hi Laurent,

Thanks very much for the reply. I haven't been given a protocol to follow.So i had to post my question here.

Thanks a lot.Its veally helpful.
Thanks

[danko]

Validation without a protocol? Hope not you’re GMP regulated!

Best Regards

[surinzp]

Yes, you are right. Not yet GMP regulated. People still in the learning process about GMP.

Thanks