C. W. GrayR. G. McLarenJ. ShiowatanaLincoln University, New ZealandMahidol University2018-07-242018-07-242003-07-15Australian Journal of Soil Research. Vol.41, No.3 (2003), 589-597000495732-s2.0-0037743389https://repository.li.mahidol.ac.th/handle/20.500.14594/20626An isotope dilution inductively coupled plasma-mass spectrometry (ICP-MS) technique, using an enriched stable Cd isotope, was applied to determine the labile fraction of Cd in 20 biosolids-amended soils. The measured labile Cd fraction was compared with the amounts of Cd solubilised or extracted by HNO3, EDTA, CaCl2, and Ca(NO3)2. Labile Cd, as a proportion of total soil Cd (% labile), ranged between 33 and 84% with a mean of 50%, indicating that a significant proportion of the Cd added to these soils from biosolids is in non-labile forms. EDTA was found to release Cd from non-labile sites, solubilising on average 30% more Cd than labile forms measured by isotope dilution. In contrast, the proportion of Ca(NO3)2-extractable Cd was significantly less than the measured labile fraction and probably represents Cd in soil solution. Extraction of soil with 1 M CaCl2, however, was found to provide a very good estimate of labile Cd in these biosolids-amended soils. Isotope dilution ICP-MS using an enriched stable Cd isotope and ICP-MS appears to be an analytical technique which has the potential to measure labile Cd in soils without the problems associated with the use of radioisotopes.Mahidol UniversityAgricultural and Biological SciencesEnvironmental ScienceConference PaperSCOPUS10.1071/SR02057