modifiers in normal phase chromatograhy

3 posts / 0 new
Last post
thirupathi
thirupathi's picture
modifiers in normal phase chromatograhy

sir/madam
i am research chemist in pharma industry.my problem is when i am using rp-hplc my product will convert in to n-1 stage(my product highly sensitive to water ).therfore i selectd   normal phase hplc .my product is highly polar compounds.when i am using silica column with n-hexane:IPA:NH3(85:15:0.2% v/v) mobile  phase .i observed  more  tailing .then i choosen cyno column now peak shape is good.
why i am selected NH3 is when i used Tri ethyl amine ,Di ethyl amine &n-butyl amine as a modifier the signal to noise ratio is more at 220 nm .
my questions are
1.can i use NH3 as a modifier.
2.can i use this  method for LOD and LOQ establishment for my product 

thanking you 

 

Dr. Analytical
Dr. Analytical's picture
Small amounts of ammonia may

Small amounts of ammonia may be acceptable, but you must test your column for stability.  Ammonia can be very reactive and it has not been tested in some columns.  Have you tried any other modifiers?

If your column is stable and your results are reproducible, then you should be able to perform all validation measurements, including LOD and LOQ.

thirupathi
thirupathi's picture
thank u sir

thank u sir