pharmacopoeia monograph suggests GC method with the ETO- standard to be prepared in the laboratory, by bubbling ETO-gas into a solution and standardizing the concentration on daily basis (before use)
now, if we replace the above procedure for analytical standard preparation with off the shelf stock solution from Sigma Aldrich (with COA.. [FONT=Calibri,Arial,Helvetica,sans-serif][FONT=Calibri,Arial,Helvetica,sans-serif]http://www.sigmaaldrich.com/catalog/product/fluka/phr1295?lang=en?ion=IN[/FONT][/FONT])
1. do we still need to standardize it on daily basis (before use)?
2. should be revalidate the analytical method?
now, if we replace the above procedure for analytical standard preparation with off the shelf stock solution from Sigma Aldrich (with COA.. [FONT=Calibri,Arial,Helvetica,sans-serif][FONT=Calibri,Arial,Helvetica,sans-serif]http://www.sigmaaldrich.com/catalog/product/fluka/phr1295?lang=en?ion=IN[/FONT][/FONT])
1. do we still need to standardize it on daily basis (before use)?
2. should be revalidate the analytical method?