Mass and HPLC

[sapna]

Why the drug should be in unionised form before reaching to the detector(MS)?

[Noser222]

It doesn't need to be, but reverse-phase retention is much better for the unionized form.

[sapna]

Can anybody say why it should be in unionised form for better retention in reversed phase chromatography?

[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.

[sapna]

Thank you

[thanth]

what is ion pair chromatography? and it's applications and what is quantom efficiency for fluorescence?

[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