Microwave extraction of heavy metals from wet rhizosphere soils and its application to evaluation of bioavailability.
Single microwave extraction of heavy metals Cr, Ni, Zn, Cu, Cd, and Pb by the extractants CaCl(2), EDTA, CH(3)COOH and HCl has been established. The experimental conditions were optimized. A microwave power of 60% and an extraction time of 25 min were adopted. Comparison of microwave extraction and conventional extraction methods revealed that results obtained by microwave techniques were generally in a good agreement with those obtained by use of extraction methods; use of the former resulted in substantial time saving and a better precision, however. Microwave extraction was used to evaluate the bioavailability of heavy metals in soils. Single correlation analysis was performed to establish the relationship between the concentrations of the extractable heavy metals in wet rhizosphere soils and their concentrations in wheat ( Troticum aestivum L.) grown on the soils under greenhouse conditions. The correlation coefficients between the extractable metals in soils and their concentrations in wheat roots were found to be 0.5398-0.7819, 0.6425-0.8073, 0.5568-0.8276, 0.5851-0.6087 for the extractants CaCl(2), EDTA, CH(3)COOH, and HCl, respectively.
Zhang
Shuzhen
S
Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, China.
Lu
Anxiang
A
Shan
Xiao-Quan
XQ
Wang
Zhongwen
Z
Wang
Songxue
S
D001682:Biological Availability; D005591:Chemical Fractionation; D002681:China; D007202:Indicators and Reagents; D019216:Metals, Heavy / Q000032:analysis / Q000302:isolation & purification* / Q000493:pharmacokinetics; D008872:Microwaves; D018517:Plant Roots; D012989:Soil Pollutants / Q000032:analysis / Q000302:isolation & purification* / Q000493:pharmacokinetics
D007202:Indicators and Reagents; D019216:Metals, Heavy; D012989:Soil Pollutants