On-line identification method in column liquid chromatography: UV resonance Raman spectroscopy

Ultra-violet resonance Raman spectroscopy (RRS) is presented as a novel ide ntification tool for conventional-size column liquid chromatography (LC). T he on-line coupling was made using a standard Z-shaped flow cell. A continu ous-wave frequency-doubled argon ion laser operating at a wavelength of 244 nm was used for excitation. "On-the-fly" resonance Raman spectra of four m odel compounds, fluorene, phenanthrene, fluoranthene, and pyrene, were reco rded after a standard acetonitrile/water reversed-phase LC separation. When applying a large-volume-injection procedure (32 mL), detection limits were at the nanogram per milliliter level. The results indicate that UV-RRS giv es detailed spectral information at an appropriate sensitivity level so tha t coupling with LC becomes feasible.