DEVELOPMENT OF COLORIMETRIC METHOD FOR THE DETECTION OF AMINES BOUND TO SOLID SUPPORT

4-N,N'-Di methylaminoazobenzene-4'-isothiocyanate (DABITC), malachite green isothiocyanate (MGI) and 2,3-indolinedione (isatin) have been ev aluated for the detection of primary aromatic and secondary aliphatic/ aromatic amines bound to polystyrene resins, Isatin was found to be an ideal reagent for the derivatisation of resine bound compounds contai ning a proline residue, Both DABITC and MGI reacted with primary and a secondary resin bound amines, However, MGI mas found to be the more u seful reagent because reaction with this dye gives distinctly coloured polystyrene beads. Beads containing bound aniline turned from brown t o green and those containing bound proline or piperazine turned from w hite to deep-blue in colour, The sensitivity of the colorimetric assay was tested by treating a resin containing partially derivatised (appr oximately 11% unreacted amine) piperazine with MGI. The resin turned f rom white to deep-blue in colour, demonstrating the presence of unreac ted piperazine.