what's best alternative to UV det. for normal phase HPLC

[Gary.A.Cain]

What type of detector is the best alternative to UV (not MS) for normal phase HPLC methods? RI, ELSD, CAD? Can these detectors handle both analytical and prep samples? What about down-time and maintenance requirements?

[Noser222]

I would say it depends more on your analytes and mobile phase than the stationary phase. RI will detect anything though it's not too sensitive and you can't run a gradient. ELSD will detect anything as long as the mobile phase is volatile and the analyte is more volatile than the mobile phase. I guess you'd have to splilt the flow from ELSD or CAD if you were doing prep work. RI is the cheapest and easiest to maintain of those three.