Investigation of metal sulfide complexes in sea water using cathodic stripping square wave voltammetry

Jia Zhong Zhang, Frank J. Millero

Research output: Contribution to journalArticle

86 Scopus citations

Abstract

Cathodic stripping square wave voltammetry has been used to detect H2S in sea water over a wide range of concentrations (nM to mM). The addition of metal ions to the solutions was found to depress the signal. This depression was attributed to the formation of metal sulfide complexes [MHS +, M(HS)2]. Stability constants for the formation of sulfide complexes with Cd2+, Cu2+, Cu+, Pb2+, Co2+, Fe2+, Mn2+, Ni2+, Hg2+ have been estimated in sea water at pH 8.0 and 25 °C using this method. The stability constants of cadmium sulfide complexes (log βCdHS = 6.3 and log βCd(HS)2 = 12.7) were found to be in reasonable agreement with previous measurements. The values of log βCuHS = Cu(HS)2 = 13.0; log βPb(HS) = 7.1 and log βPb(HS)2 = 13.5; log βZnHs = 6.0 and log βZn(HS)2 = 13.7, log βFeHS = log βCoHS = log βNiHS = 5.3 and log βMnHS = 6.7 were also obtained. Correction for the formation of strong chloro complexes for Hg2+ and Cu+ in sea water gave measured values close to the literature values. The results have been used to determine the speciation of HS- in surface sea water and of a number of metal ions in various anoxic basins.

Original languageEnglish (US)
Pages (from-to)497-504
Number of pages8
JournalAnalytica Chimica Acta
Volume284
Issue number3
DOIs
StatePublished - Jan 10 1994

Keywords

  • Sea water
  • Stripping voltammetry
  • Waters
  • metal sulfide complexes

ASJC Scopus subject areas

  • Analytical Chemistry
  • Biochemistry
  • Environmental Chemistry
  • Spectroscopy

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