The reaction of 3,8,13,18-tetramethyl-21H,23H-porphine-2,7,12,17-tetrapropionic acid or coproporphyrin-I (CPI) with mercury(II) was studied spectrophotometrically, and kinetic and equilibrium constants were determined; the influence of temperature on the reaction rate was also studied. It was verified that mercury(II) accelerates the incorporation reaction of cobalt(II) into CPI; the kinetics and mechanism of this reaction at high alkaline pH were studied. Sensitive kinetic methods for the determination of mercury(II) at ppb levels have been established; the apparent molar absorbivity and Sandell's sensitivity for the recommended procedure, at 368 nm, and 400 s after the start of the reaction, were: 4.23×105 (l mol−1cm−1) and 0.474 (ng cm−2) (for A=0.001).
Kinetic and equilibrium studies on mercury(II)-coproporphyrin-I. Metal ion exchange reaction with cobalt(II) and application to determination of trace mercury(II)
GIOVANNETTI, Rita;BARTOCCI, Vito
1998-01-01
Abstract
The reaction of 3,8,13,18-tetramethyl-21H,23H-porphine-2,7,12,17-tetrapropionic acid or coproporphyrin-I (CPI) with mercury(II) was studied spectrophotometrically, and kinetic and equilibrium constants were determined; the influence of temperature on the reaction rate was also studied. It was verified that mercury(II) accelerates the incorporation reaction of cobalt(II) into CPI; the kinetics and mechanism of this reaction at high alkaline pH were studied. Sensitive kinetic methods for the determination of mercury(II) at ppb levels have been established; the apparent molar absorbivity and Sandell's sensitivity for the recommended procedure, at 368 nm, and 400 s after the start of the reaction, were: 4.23×105 (l mol−1cm−1) and 0.474 (ng cm−2) (for A=0.001).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
