Summary
A very sensitive electrochemical stripping procedure for trace measurements of iron(III) is described. The chelate of iron with Solochrome Violet RS is adsorbed on the hanging mercury drop electrode, and the reduction current of the accumulated chelate is measured by voltammetry. The adsorption and redox behaviours are explored by cyclic voltammetry. The height of the chelate peak, which is about 0.28 V more negative than the peak of the free dye, is shown to be proportional to the iron concentration. Optimal experimental conditions include a preconcentration potential of −0.40 V, solution pH of 5.1 and a linear scan mode. The sharp chelate peak, associated with the effective interfacial accumulation, coupled with the flat baseline, facilitates measurements at the nanomolar and submicromolar concentration levels using short preconcentration times. The limit of detection after 1 min preconcentration is 0.04 μgl−1 (7 × 10−10 M), and the relative standard deviation at the 10−7 M level is 4.7%. The effects of possible interferences, due to coexisting metal ions or organic surfactants, are evaluated. The ability of measuring iron(III) in the presence of iron(II) is illustrated. Actual analyses of sea and tap waters are reported.
Similar content being viewed by others
References
Lingane JJ (1946) J Am Chem Soc 68:68
Meites L (1948) Anal Chem 20:895
Parry EP, Anderson DP (1973) Anal Chem 45:2401
Beyer ME, Bond AM, McLaughlin RJW (1975) Anal Chem 47:479
Latimer GW (1968) Talanta 15:1
Rooney RC, McIver PJ (1962) Analyst 87:895
Wang J (1985) Stripping analysis: Principles, instrumentation and applications. VCH Publishers, Deerfield Beach
Neeb R (1969) Inverse Chemie und Voltammetrie. Verlag Chemie, Weinheim
Vydra F, Stulik K, Julakova E (1976) Electrochemical stripping analysis. Ellis Horwood Ltd, Chichester
Berge H, Drescher A (1967) Fresenius Z Anal Chem 231:11
Brainina KhZ, Roizenblat EM (1963) Zh Anal Khim 18:1392
Monien H, Jacob P (1972) Fresenius Z Anal Chem 260:195
van den Berg CMG, Huang ZQ (1984) J Electroanal Chem 177:269
Wang J, Farias PAM (1985) Anal Chim Acta 172:57
Wang J, Mahmoud JS (1986) J Electroanal Chem 208:383
Florence TM, Belew WL (1969) J Electroanal Chem 21:157
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Wang, J., Mahmoud, J. Chelate adsorption for trace voltammetric measurements of iron(III). Z. Anal. Chem. 327, 789–793 (1987). https://doi.org/10.1007/BF00511909
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00511909