A review of luminescent assays has been published by L. J. Kricka, Clinical Chemistry 37, 1472-1481 (1991).

SUMMARY OF THE INVENTION

It has now been found that certain organoboron compounds are effective enhancers of chemiluminescence in a reaction between a dihydrophthalaztnedione (DPD), a peroxidase enzyme catalyst and an oxidant. The enhancers of the present Invention include compounds of formula which R, W, X, Y and Z have the following meanings; R is selected from hydrogen, n-butyl, O,O-propylene (a cyclic ether), 4'-chlorophenyl and 3',5'-dichlorophenyl, W is selected from hydrogen, hydroxy, methyl, methoxy and chloro, X Is selected from hydrogen, methyl, chloro, amino and nitro, Y is selected from hydrogen, methyl, carboxy, chloro, bromo, iodo, phenyl, phenoxy, 4'-chloroanilino, 4'-boronylphenyl, 4'-bromophenyl, 2'-carboxyethenyl and trimethylsilyl, Z is selected from hydrogen, 5-chloro, 5-bromo, 5-(3'-trifluoromethyl)phenylazo, or 6-chloro, W and X together may represent a fused benzene ring and X and Y together may represent a fused benzene ring substituted by hydroxy in the 6 position of the naphthalene ring numbering, provided that