Analytical and Bioanalytical Chemistry

, Volume 382, Issue 2, pp 347–352

Use of ICP and XAS to determine the enhancement of gold phytoextraction by Chilopsis linearis using thiocyanate as a complexing agent

  • Jorge L. Gardea-Torresdey
  • Elena Rodriguez
  • Jason G. Parsons
  • Jose R. Peralta-Videa
  • George Meitzner
  • Gustavo Cruz-Jimenez
Special Issue Paper

DOI: 10.1007/s00216-004-2966-6

Cite this article as:
Gardea-Torresdey, J.L., Rodriguez, E., Parsons, J.G. et al. Anal Bioanal Chem (2005) 382: 347. doi:10.1007/s00216-004-2966-6

Abstract

Under natural conditions gold has low solubility that reduces its bioavailability, a critical factor for phytoextraction. Researchers have found that phytoextraction can be improved by using synthetic chelating agents. Preliminary studies have shown that desert willow (Chilopsis linearis), a common inhabitant of the Chihuahuan Desert, is able to extract gold from a gold-enriched medium. The objective of the present study was to determine the ability of thiocyanate to enhance the gold-uptake capacity of C. linearis. Seedlings of this plant were exposed to the following hydroponics treatment: (1) 5 mg Au L−1 (2.5×10−5 mol L−1), (2) 5 mg Au L−1+10−5 mol L−1 NH4SCN, (3) 5 mg Au L−1+5×10−5 mol L−1 NH4SCN, and (4) 5 mg Au L−1+10−4 mol L−1 NH4SCN. Each treatment had its respective control. After 2 weeks we determined the effect of the treatment on plant growth and gold content by inductively coupled plasma–optical emission spectroscopy (ICP–OES). No signs of shoot-growth inhibition were observed at any NH4SCN treatment level. The ICP–OES analysis showed that addition of 10−4 mol L−1 NH4SCN increased the concentration of gold by about 595, 396, and 467% in roots, stems, and leaves, respectively. X-ray absorption spectroscopy (XAS) studies showed that the oxidation state of gold was Au(0) and that gold nanoparticles were formed inside the plants.

Keywords

Gold Phytoextraction Chilopsis linearis ICP–OES XAS Complexing agents 

Copyright information

© Springer-Verlag 2005

Authors and Affiliations

  • Jorge L. Gardea-Torresdey
    • 1
    • 2
    • 2
  • Elena Rodriguez
    • 1
  • Jason G. Parsons
    • 2
  • Jose R. Peralta-Videa
    • 2
  • George Meitzner
    • 1
    • 2
  • Gustavo Cruz-Jimenez
    • 1
  1. 1.Environmental Science and Engineering PhD ProgramUniversity of Texas at El PasoEl PasoUSA
  2. 2.Chemistry DepartmentUniversity of Texas at El PasoEl PasoUSA

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