MODULAR RECORDING TITRIMETER FOR USE WITH LUMINESCENT ENDPOINT DETECTION.

A recording titrimeter for use with luminescent endpoint detection is described. The titrimeter consists of a low-cost photomultiplier tube. The titrimeter consists of a low-cost photomultiplier tube, regulated high voltage supply, electrometer, chart recorder, and peristalic pump. A reaction cell based upon a 10 mm pathlength spectrophotometer cuvet and suitable for luminescence detection at high ambient light level is also described. The precision attainable with the titration system was determined with an acid-base titration using a modified reaction cell suitable for photometric titrations. A procedure suitable for determining Ca** plus **2 in the presence of at least five-fold Mg** plus **2 at the nanomole level is described, using the luminol-hydrogen peroxide reaction as the endpoint indicator.