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

A simple, flexible, and inexpensive peroxyoxalate chemiluminescence de tection 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 zer o dead-volume and the following features: (a) highly flexible optimiza tion of chemical variables affecting the peroxyoxalate chemiluminescen ce reaction, which can take place outside the chromatographic system; (b) use of high oxidant/oxalate ester concentration ratios, which decr ease 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 rap id under the selected experimental conditions), The proposed detection system was tested in the high-performance liquid chromatographic dete rmination of polycyclic aromatic hydrocarbons, where it exhibited high er sensitivity (limits of detection in the femtomole range) than exist ing alternatives.