ZERO-DEAD-VOLUME PEROXYOXALATE CHEMILUMINESCENCE DETECTION IN LIQUID-CHROMATOGRAPHY

A simple, flexible, and inexpensive peroxyoxalate chemiluminescence detection reactor for liquid chromatography is reported, This postcolumn device permits the efficient mixing of the mobile phase and reactants, bis(2,4,6-trichlorophenyl) oxalate and hydrogen peroxide, with a zero dead-volume and the following features: (a) highly flexible optimization of chemical variables affecting the peroxyoxalate chemiluminescence reaction, which can take place outside the chromatographic system; (b) use of high oxidant/oxalate ester concentration ratios, which decrease background emission and increase the signal/noise ratio; and (c) use of large reaction volumes in the detection cell without excessive additional band broadening (the chemiluminescence reaction is very rapid under the selected experimental conditions), The proposed detection system was tested in the high-performance liquid chromatographic determination of polycyclic aromatic hydrocarbons, where it exhibited higher sensitivity (limits of detection in the femtomole range) than existing alternatives.