Profiling of impurities in heroin by capillary electrochromatography and laser-induced fluorescence detection

Capillary electrochromatography (CEC) with laser-induced fluorescence (LIF) detection was investigated for the analysis of acidic and neutral impurities in heroin. The phenanthrene-like heroin impurities exhibit high native fluorescence when excited with a doubled argon ion laser (operating at 257 nm). The limit of detection for acetylthebaol is 66 pg ml−1. CEC–LIF analysis of heroin samples of different geographical origin gave distinguishable peak-enriched chromatograms. A sulfonic acid C12 polymer monolith column provided similar resolving power to a 1.5 mm non-porous ODS column for the isocratic analysis of a refined heroin sample. Analysis of a crude heroin sample via a multi-step gradient CEC resolved a significantly higher number of peaks than gradient high-performance liquid chromatography or micellar electrokinetic capillary chromatography.