Evaluation of n-substituted aminosulfonic acid pH buffers with a morpholinic ring for cadmium and lead speciation studies by electroanalytical techniques

• Published in: Analytica chimica acta Vol. 394; no. 2; pp. 325 - 335
• Main Authors: Soares, Helena M.V.M, Conde, Paula C.F.L, Almeida, Alexandra A.N, Vasconcelos, M.Teresa S.D
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 09.08.1999; Elsevier
• Subjects: 2-( N-morpholino)ethanesulfonic acid; 3-( N-morpholino)-2-hydroxypropanesulfonic acid; 3-( N-morpholino)propanesulfonic acid; Analytical chemistry; Cadmium; Chemistry; Cyclic voltammetry; Differential pulse anodic stripping voltammetry; Differential pulse polarography; Electrochemical methods; Exact sciences and technology; Lead; pH buffers; Cyclic voltammetry; Cadmium; Differential pulse polarography; Differential pulse anodic stripping voltammetry; pH buffers; Lead; 2-( N-morpholino)ethanesulfonic acid; 3-( N-morpholino)propanesulfonic acid; 3-( N-morpholino)-2-hydroxypropanesulfonic acid; Electrode adsorption; Ligand effect; Chemical analysis; Electrochemical method; Anodic stripping voltammetry; Organic ligand; Lead Complexes; Transition metal Complexes; Buffer solution; Metal Complexes; Chemical enrichment; Pulse polarography; Multicomponent analysis; Cadmium Complexes; Aqueous solution; Speciation; Quantitative analysis
• ISSN: 0003-2670; 1873-4324
• DOI: 10.1016/S0003-2670(99)00294-9

The electrochemical behavior of cadmium and lead metal ions was investigated in the presence of different pH buffers [3-( N-morpholino)-2-hydroxypropanesulfonic acid (MOPSO), 2-( N-morpholino)ethanesulfonic acid (MES) and 3-( N-morpholino)propanesulfonic acid (MOPS)] by various methods [differential pulse anodic stripping voltammetry (DPASV), differential pulse polarography (DPP) and cyclic voltammetry (CV)]. The complexation and/or adsorption properties of these pH buffers were also examined. Conclusions about the possible influences of these pH buffers on the speciation studies of cadmium and lead metal ions are drawn. MES, MOPSO and MOPS can be suitable pH buffers for determination of both metals by DPP and DPASV as they do not complex these metals and do not modify to a significant extent the reversibility of the electrochemical processes under the experimental conditions used.