Journal of the Iranian Chemical Society

, Volume 11, Issue 2, pp 415–422

Determination of manganese (VII), chromium (VI) and nickel (II) in medicinal herb samples by cloud-point extraction and high-performance liquid chromatography

  • Deqing Zou
  • Ye Qing
  • Yingtang Li
  • Mosheng Liu
  • Yaling Yang
Original Paper

Abstract

A highly sensitive method for the determination of manganese (VII), chromium (VI) and nickel (II) in medicinal herb samples is proposed. The method is based on analytes reacted with ammonium pyrrolidinedithiocarbamate (APDC) to give hydrophobic chelates (M–APDC), which were separated and enriched by cloud-point extraction (CPE) with non-ionic surfactant Tergitol TMN-6 as extractant. The surfactant-rich phase containing the chelates is determined with a high-performance liquid chromatography system. To achieve the best CPE method, the Box–Behnken design was used to study the concentration of Tergitol TMN-6, equilibrium temperature, equilibrium time as well as their interaction. What followed was the individual research for the pH of the sample solutions and the concentration of APDC. What is more, in the given optimized experimental conditions, calibration plots were found to be linear in the range of 0.0200–0.500 mg/L for Mn (VII) and Cr (VI), meanwhile 0.0500–1.00 mg/L for Ni (II), the linear correlation coefficients were between 0.996 and 0.999, the recoveries ranged from 91.8 to 97.8 % and the relative standard deviations were between 1.09 and 2.30 % (n = 3). The limits of detection were 0.164 μg/L for Mn (VII), 0.562 μg/L for Cr (VI) and 5.12 μg/L for Ni (II), respectively. The proposed method was applied to determine manganese (VII), chromium (VI) and nickel (II) in medicinal herb samples with satisfactory results.

Keywords

High-performance liquid chromatography Ammonium pyrrolidinedithiocarbamate Box–Behnken design Cloud-point extraction Medicinal herbs 

Copyright information

© Iranian Chemical Society 2013

Authors and Affiliations

  • Deqing Zou
    • 1
  • Ye Qing
    • 2
  • Yingtang Li
    • 1
  • Mosheng Liu
    • 1
  • Yaling Yang
    • 1
  1. 1.Faculty of Life Science and TechnologyKunming University of Science and TechnologyKunmingChina
  2. 2.Kunming Productivity Promotion CenterKunmingChina

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