A new polymeric chromogenic reagent, poly[allylamine-co-N-4-(8-aminoquinolyl-5-azo)benzylideneallylamine] (PA-PPQ), has been synthesized by condensing polyallylamine (PA) with _5-(4-formylphenylazo)-8-aminoquinoline
(PPQ), and its properties studied. In alkaline media, PA-PPQ reacts with copper(I1) to form a water-soluble brown complex, whose absorption maximum is at 590 nm. The molar absorptivity (E) of the complex is 4.1 x lo4 1 mol-' cm-', and Beer's law is obeyed over the range O-l.0 ug ml-' of copper. Compared to the corresponding low molecular weight PPQ and other heterocyclic azo-chromogenic reagents, PA-PPQ offers considerably improved solubility in water and good selectivity for copper( which may be attributed to the incorporation of PPQ into a water-soluble polymer and the effect of the polymeric chain on both reactivity and the reaction microenvironment of the reagent. Also, a simple and selective spectrophotometric method for the determination of copper has been developed and satisfactorily applied to aluminium alloy and bovine liver samples.