The reaction conditions and component ratios were established for the attachment of 4-(2-pyridylazo)resorcinol (PAR), 1-(2-pyridylazo)-2-naphthol
(PAN) and 8-hydroxyquinoline (8-HQ) to the silica surface by means of a single-stage Mannich reaction. The modified sorbents
that were synthesized were characterized by an adsorption method, and DRIFT and UV spectroscopies. The concentrations of PAR,
PAN and 8-HQ grafted to the silica surface that were attained were 2.810−5, 8.510−5 and 2.710−4 mol g−1, respectively.