Spectrofluorimetric determination of trace amounts of Ga(III) in aluminium and biological samples with 1-(2-pyridylazo)-2-naphthol in sodium dodecyl sulphate micellar medium

Summary A spectrofluorimetric method is proposed for the determination of gallium with 1-(2-pyridylazo)-2-naphthol as derivative reagent in sodium dodecyl sulphate micellar medium. Sensitivity is increased by a factor of 20 with respect to that obtained in 20% ethanol medium. The stoichiometry of the complex is 11. Optimum working conditions are about pH 4, 0.3% sodium dodecyl sulphate and absence of ethanol. The calibration graph is linear in the range 5–400 ppb of Ga(III) with a variation coefficient of 1.5% at 210 ppb of Ga for 10 replicates, and detection limit is 0.8 ppb. Main interferences are from copper and cobalt. Results obtained in the determination of Ga(III) in urine and aluminium samples show the validity of the method proposed.

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Spektrofluorimetrische Bestimmung von Spuren Ga(III) in Aluminium und biologischen Proben mit 1-(2-Pyridylazo)-2-naphthol in micellarem Natriumdodecyl-sulfatmedium