Please share your experience for validation method of analysis (residual solvents in API). I found difficulties to have consistent result for accuracy (recovery 80-120%). But if I do the routine assay for residual solvent, the result is quite consistent.
Thank you
In which form are you doing the HS? That will affect your accuracy. Could you explain it with more detail? Thanks
I prepare my sample (100 mg of powder) in dimethylformamide spiked with acetonitrile and isopropyl alcohol with concentration 50%, 100% and 150%, respectively. Thank you
Hello Febry
I still understand some things.
You weight 100mg of power in a balance that has which minimum weight according with USP?
How much DMFA you add to the power?
In which type of vial you put it and which type of septum you use?
How you prepare the concentration of 50% 100% and 150% of acetonitrile and isopropyl alcohol? Best regards
Hi Eleuterio,
Thank you, just read your message. Yes my balance already fulfilled the requirement.
100 mg powder add with 1 ml dimethylformamide, 1 ml acetonitrile and 1 ml isopropyl alcohol to a glass vial for GC HS with rubber septum
I prepare acetonitrile and isopropyl alcohol by pipet to a volumetric flask and dilute up to 50% 100% and 150% concentration
I hope you can understand
For VOCs always use silicon septum with Teflon fase in contact with the inner part of the vial. Rubber absorbed organic compounds.
HS partial vapor pressure is sensitivity to others volatiles compounds in the mixture. So if you want to see acetonitrile don´t add acetonitrile to the sample.
Standard additions method is not good for HS. If you want to do it, add the lowest nivel of it.
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