Speciation analysis of manganese in tea samples using flame atomic absorption spectrometry after cloud point extraction


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Yalçın S. , Filik H. , Apak R.

JOURNAL OF ANALYTICAL CHEMISTRY, vol.67, no.1, pp.47-55, 2012 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 67 Issue: 1
  • Publication Date: 2012
  • Doi Number: 10.1134/s1061934812010194
  • Title of Journal : JOURNAL OF ANALYTICAL CHEMISTRY
  • Page Numbers: pp.47-55
  • Keywords: Cloud point extraction (CPE), Mn(II) speciation, tea leaves, XAD-resin, SIZE-EXCLUSION CHROMATOGRAPHY, OPTICAL-EMISSION SPECTROMETRY, PLASMA-MASS SPECTROMETRY, SOLID-PHASE EXTRACTION, WATER SAMPLES, NATURAL-WATER, PRECONCENTRATION, INFUSIONS, MILK, SEPARATION

Abstract

The speciation of Mn(II) in tea infusion was studied using cloud point extraction (CPE). In tea infusion, the flavonoid-bound Mn(II) was extracted at pH 5.0 using Triton X-100 (TX-100), the remaining free aquated Mn(II) and weakly-complexed Mn(II) in solution were both chelated with 8-hydroxyquinoline (HOx) and CPE-preconcentrated with TX-100. The enriched analyte was determined by flame AAS. The optimal concentrations for CPE of 0.02 ppm Mn were as follows: TX-100, 0.2% (v/v); HOx, 1.0 x 10(-4) M; NaCl, 1.0% (w/v). LOD was 1.9 mu g/L with a preconcentration factor of 10-20. The method was validated using a standard XAD-resin separation procedure and applied to synthetic seawater and CRM samples.