Adaptation of a commercial capillary electrophoresis instrument for chemiluminescence detection

Modification of a commercial CE instrument (HP 3D-CE, or Agilent G1602A) to adapt it for chemiluminescence (CL) detection is described. The reversible modification involves interchanging the deuterium lamp (used for standard absorbance detection) with a sidearm photomultiplier tube in the lamp housing. Power supply and amplification circuitry is added via an external breadboard, and the amplified CL signal is recorded via a recorder/integrator. The viability of the CL detector was demonstrated with both pressure rinses and electrophoresis of chemiluminescent samples. Peak area precision was 1.5% RSD for pressure rinses of a peroxyoxalate ("lightstick") sample and 4.0% RSD for electrophoresis of 100 mu M luminol (catalyzed by horseradish peroxidase). The CL peak area was linear with concentration for electrophoresis of luminol (10-s injections) from at least 1.0-50 mu M.