By Fabiano on Friday, October 10, 2003 - 05:35 am:
What are the practical limitations of use a spike and recovery tests instead of internal standards?
I am analyzing sugars and I found that 3 or 4 spikes gave me a much better result than an internal standard regarding the extraction step losses.
Can I include this procedure in my method for routine analysis?
By Anonymous on Friday, October 10, 2003 - 07:40 am:
I work for a U.S. OTC pharmaceutical company. All of our cGMP HPLC test methods are external standard, using autosamplers for precision. Our test method validations were all done by spiking placebo product and documenting our recoveries. So our QC facilities and R&D both use external standard 99% of the time, modern autosamplers are very precise. I would stay away from any manual injections.
By Fabiano on Friday, October 10, 2003 - 01:34 pm:
Ok, But pharmaceutical companies usually do not perform extractions, just dissolution.
I also use an autosampler and external standard.
I am not doing the spikes for standard addition calibration, is just for correct my losses in extraction.
By Anonymous on Friday, October 17, 2003 - 08:40 am:
Standard addition is ideal when there can be adsorbtion interference from the sample matrix or competitive solvation between the analyte, standard, and solvent.