COMPARISON OF THE SOLUTION LUMINESCENCE PROPERTIES AND SOLID-MATRIX LUMINESCENCE PROPERTIES OF 2-AMINO-1-METHYL-6-PHENYLIMIDAZO[4,5-B]PYRIDINE

The solution fluorescence properties of 2-amino-1-methyl-6-phenylimida zo[4,5-b]pyridine (PhIP) were compared with the solid-matrix luminesce nce properties of PhIP. The fluorescence properties were obtained in e thanol and several binary solutions of ethanol:water. An ethanol solut ion of PhIP gave a very strong fluorescence signal and the ethanol:wat er solutions only showed a small increase in the fluorescence signal. acidic solutions of PhIP in ethanol:water (7:3) showed a major decreas e in fluorescence intensity with at HCl of 10(-4) M and greater, but N aOH solutions of PhIP did not affect the fluorescence intensity to any great extent. Both acidic and basic solutions gave fluorescence emiss ion spectra that were shifted to longer wavelengths. Solid-matrix room -temperature fluorescence (SMRTF) and solid-matrix room-temperature ph osphorescence (SMRTP) were readily obtained on filter paper. SMRTP sho wed some distinct advantages over SMRTF and gave a limit of detection of 0.2 ng on filter paper. Several aspects of both solution luminescen ce and solid-matrix luminescence of PhIP are discussed.