Characterization of organotin species using microbore and capillary liquid chromatographic techniques with an epifluorescence microscope as a novel imaging detector.

The novel application of a UV epifluorescence microscope as an imaging detector for microbore and capillary high-performance liquid chromatography (HPLC) is reported. The microscope is focused on an in-line quartz flow cell incorporated down stream of a microbore HPLC column or directly on an optically clear portion of fused-silica capillary columns for analyte detection. The effect of different fluorescent ligand to analyte ratios on detection limits is also reported, as well as the effect of different image volume sizes produced by changes in microscope objective lens magnification power. Determination of relative sensitivities an detection limits for methyl- and butyltin compounds, complexed with fluorescent dyes, reveals that the organotins show decreasing sensitivity as the number of alkyl substituents on the tin atom increases, with minimum detectable amounts of 6-160 pg of analyte-ligand complex.