FLUORESCENCE REACTION AMONG N-(PHENYL)-N-(4-METHYLQUINOLINYL) AMINE DERIVATIVES, HYDROGEN-PEROXIDE AND COBALT(II), AND ITS APPLICATION

The fluorescence reactions among seven N-(phenyl)-N-(4-methylquinolinyl)amine derivatives, hydrogen peroxide as a redox agent and cobalt(II), in the presence or absence of various surfactants, were systematically investigated. The order of the relative fluorescence intensities (R.fl.Int.) of these fluorescence products were N-(4'-hydroxyphenyl)-N-(4-methylquinolinyl)amine(IV), N-(2'-hydroxyphenyl)-N-(4-methylquinolinyl)amine(II) > N-(3'-hydroxy-4'-carboxyphenyl)-N-(4-methyquinolinyl)amine(MQAS)(VII) > N-(3'hydroxyphenyl)-N-(4-methylquinolinyl)amine(III) > N-(phenyl)-N-(4-methylquinolinyl)amine(I) > N-(4'-carboxyphenyl)-N-(4-methylquinolinyl)amine(V) > N-(3'-carboxyphenyl)-N-(4-methylquinolinyl)amine(VI) fluorescence products. Especially, the R.fl.Int. using (IV) in the presence of cationic surfactants in basic media was most large and stable, and a simple, rapid and sensitive spectrofluorometric method for the determination of cobalt(II) using (IV) and hydrogen peroxide in the presence of trimethylstearylammonium chloride(STAC) was proposed without the need of organic solvent extraction. The calibration graph was linear in the range of 0.2 to 15 ng cobalt(II) per 10 ml at 522 nm emission wavelength with excitation wavelength of 410 nm, and was about 3-fold more sensitive than the previous method with (IV).