High-Performance Liquid Chromatography Interfaced with Fluorescence Line-Narrowing Spectroscopy for On-Line Analysis

We have demonstrated, for the first time, that high-performance liquid chromatography (HPLC) can be interfaced with fluorescence line-narrowing spectroscopy (FLNS) for on-line identification and characterization of analytes. Interfacing centered primarily on the design and construction of a novel liquid helium cryostat that accommodates variable-sized quartz tubes/capillaries suitable for HPLC as well as capillary electrophoresis/electrochromatography. In addition to the high spectral resolution afforded by FLNS, analyzing the separated components at 4.2 K minimizes photodegradation from the excitation source and provides indefinite detection times for signal averaging. The proof-ofprinciple for the HPLC-FLNS system is first demonstrated with a mixture of four structurally similar polycyclic aromatic hydrocarbons and then applied to the analysis of DNA adducts from mouse skin exposed to the carcinogen dibenzo[a,l]pyrene. With femtomole detection limits, HPLC-FLNS can be used for real-world analyses of complex mixtures.