Collect. Czech. Chem. Commun. 1982, 47, 2654-2675
https://doi.org/10.1135/cccc19822654

Effective spectrophotometric study of the complexation reactions of 2-(2-pyridylazo)-1-naphthol-4-sulphonic acid with Zn(II) and Cd(II) using the SQUAD-G program

Luděk Jančář, Josef Havel, Vlastimil Kubáň and Lumír Sommer

Department of Analytical Chemistry, J. E. Purkyně University, 611 37 Brno

Abstract

The existence of the red-orange protonated MLH complexes (λmax = 490 nm, εmax = 16 700 mmol-1 cm2, log *β111 = -0.51 for Zn(II) and λmax = 490 nm, εmax = 20 800 mmol-1 cm2, log *β111 = -1.28 for Cd(II)) and of the red-purple ML and ML2 complexes (λmax = 517 nm, εmax = 27 500 mmol-1 cm2, log *β112 = -2.8 and λmax = 527 nm, εmax = 61 500 mmol-1 cm2, log *β124 = -6.0 for Zn(II) and λmax = 522 nm, εmax = 27 200 mmol-1 cm2, log *β112 = -3.9 and λmax = 522 nm, εmax = 52 000 mmol-1 cm2, log *β124 = -8.2 for Cd(II) ions) was demonstrated in aqueous medium by numerical interpretation of the absorbance curves by the SQUAD-G minimization program. Conditions were proposed for development of a spectrophotometric method for the determination of Zn(II) and Cd(II) using 1-PAN-4S.