Improving Detection Limits

[sra37]

I'm quite new to this, so bear with me. I am wondering if any of you have any tips for improving the detection limit of HPLC coupled with UV-Vis? So far I can't detect as low as I would like.

Is there anything I can do to improve this? (eg instrument settings, elution solvents, etc)

[prepcolumn]

at first glance you may; increase concentration, increase injection volume..

[Consumer Products Guy]

Better wavelength, solvents with less background absorbance, using gradient elution to sharpen peaks, actually diluting samples with water so a larger quantity can be injected without hurting peak shapes (I forget the term for this).

[DR]

Don't forget that sometimes a narrower bore column can also help - eg: going from 4.6mm to 3mm.

[Johnny Rod]

Anything that speeds up chormatography to turn wider peaks into taller peaks e.g. column temperature. Provided youre peaks are sufficiently resolved, you don't need glacial valleys between them

[rrm1987]

look for some derivitisation agents which will enhance the UV-VIS absorbance.For which compound you would like to improve the sensitivity

[sra37]

Thanks for the suggestions everyone, I will have a play around with some of these ideas and see if anything works.