On-Line Identification Method in Column Liquid Chromatography: UV Resonance Raman Spectroscopy

Ultraviolet resonance Raman spectroscopy (RRS) is presented as a novel identification tool for conventional-size column liquid chromatography (LC). The on-line coupling was made using a standard Z-shaped flow cell. A continuous-wave frequency-doubled argon ion laser operating at a wavelength of 244 nm was used for excitation. "On-thefly" resonance Raman spectra of four model compounds, fluorene, phenanthrene, fluoranthene, and pyrene, were recorded after a standard acetonitrile/water reversedphase LC separation. When applying a large-volumeinjection procedure (32 mL), detection limits were at the nanogram per milliliter level. The results indicate that UVRRS gives detailed spectral information at an appropriate sensitivity level so that coupling with LC becomes feasible.