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Mass and HPLC

Posted: Sat Dec 16, 2006 3:48 pm
by sapna
Why the drug should be in unionised form before reaching to the detector(MS)?

Posted: Sat Dec 16, 2006 4:02 pm
by Noser222
It doesn't need to be, but reverse-phase retention is much better for the unionized form.

Posted: Wed Dec 20, 2006 12:19 pm
by sapna
Can anybody say why it should be in unionised form for better retention in reversed phase chromatography?

Posted: Wed Dec 20, 2006 2:06 pm
by Uwe Neue
The ionization makes the compound more polar. With other words, a positively charged amine is more polar than the non-ionic amine, and a negatively charged carboxylic acid is more polar than the non-ionized form. Less polar = more retention in RPLC.

Posted: Mon Dec 25, 2006 3:16 pm
by sapna
Thank you

Re: Mass and HPLC

Posted: Mon Jan 08, 2007 8:48 am
by thanth
what is ion pair chromatography? and it's applications and what is quantom efficiency for fluorescence?

Re: Mass and HPLC

Posted: Sun Jan 21, 2007 12:11 pm
by thanth
Why the drug should be in unionised form before reaching to the detector(MS)?
There is no ionization occurs but there is partially polarisation due to solvent effect

Thanth Savji