HPLC and quercetin

I've been running my HPLC for the last few feeks to check the retention time of few (single) standard flavonoids and their UV spectra. I expected the peaks would have come out when I monitored at 280nm and 365nm but the apparently life is not that simple. My quercetin standard didn't produce any peak at 365nm. Maybe the standard has degraded over time. I just received another unopened bottle of quercetin. So let see if this one is any different from the previous one
- HPLC: Waters Alliance with PDA detector
- Temp: 30degC
- Column:
- Flow rate: 0.2ml/min
- Mobile phase: ACN, MeOH



Tag: HPLC, Waters 2695 Alliance, PDA