Spectrophotometric investigation of the uranyl-phenylephrine system

Abstract

Using spectrophotometric methods and pH-metric measurements, it was found that the uranyl ion and phenylephrine form a 1:2 complex in the pH region 2.50-4.25 with two absorption maxima at 314.2 nm and 340.6 nm. The thermodynamic stability constant at I = 0 and T=298 K (room temperature) of the UO2(II)-phenylephrine complex, UO2(C9H12O2N)2, is log 0 β 2= 14.0 and ΔG2= -79.6 kJ mol-1. A linear dependence of the absorbance at 340.6 nm on the concentration of phenylephrine was obtained in the range from 0.0025 mol dm-3 to 0.0245 mol dm-3 using a solution of 0.025 mol dm-3 UO2(NO3)2 at pH = 3.90 and I = 0.075 mol dm-3. The measurement error was 2.1%. .

Primenom spektrofotometrijskih metoda i pH-metrijskih merenja utvrđeno je da UO2(II)-jon i fenilefrin grade 1:2 kompleks u oblasti rN 2,50 - 4,25 sa dva apsorpciona maksimuma na 314,2 nm i 340,6 nm. Termodinamička konstanta stabilnosti kompleksa UO2(II)-fenilefrin, UO2(C9H12O2N)2, na I = 0 i na sobnoj temperaturi (25°C) iznosi log 0 β 2 = 14,0, a ΔG2= = -79,6 kJ mol-1. Linearna zavisnost apsorbancije od koncentracije fenilefrina u vodenom rastvoru UO2(NO3)2 koncentracije 0,025 mol dm-3 na 340,6 nm dobijena je u intervalu 0,0025-0,0245 mol dm-3 na pH 3,90 i I = 0,075 mol dm-3. Greška merenja iznosi 2.1%. .