Collect. Czech. Chem. Commun. 1989, 54, 2674-2682

The FIA determination of lead with 4-(2-pyridylazo)resorcinol after preconcentration on a microcolumn of a chelating sorbent

Vlastimil Kubáň and Radim Bulawa

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


Lead can be determined conveniently by the classical or reversed FIA technique using photometric detection with 4-(2-pyridylazo)resorcinol ( cPAR = 0.1 mol l-1) in 0.1M borate buffer (λ 518 nm). For injected volumes of 50 μl, the lead concentrations can lie in the regions of 1-20 and 0.4=18 μmol l-1, respectively. The selectivity of determination can be increased one to two orders of magnitude by masking with a mixture of EDTA ( 5 μmol l-1), tartaric acid (20 μmol 1-1) and KCN (2 mmol 1-1). When combining the analysis with preconcentration on a 3 x 30 mm microcolumn of Spheron Oxin 1 000 chelating sorbent from 0.01M ammonium acetate solutions at pH 6.5 followed by elution with 0.1M-HCl, lead can be determined in concentrations of 0.1–1.2, 0.02–0.85 or 0.01–0.60 μmol 1-1 for sample volumes of 5, 10 or 20 ml, respectively. The repeatability of determination for ten independent measurements on 5, 10 and 20 ml sample volumes at cPb = 0.2, 0.05 μmol 1-1, respectively, was better than 4.7, 2.8 and 6.2%, respectively. The methodi of preconcentration on a chelating sorbent was applied to the analysis of clean industrial wastewaters. The relative deviation of the lead concentration did not exceed 6.5% in comparison with data obtained by AAS.