Equilibrium Speciation of Cadmium, Copper, and Lead in Soil Solutions
Bibliographic record
Abstract
Abstract Determination of chemical speciation of trace metals may help us to better understand the bioavailability and toxicity to living organisms in terrestrial and aquatic environments. This paper reports the speciation data of cadmium (Cd), copper (Cu), and lead (Pb) in soil solutions sampled from areas around metal smelters. A column ion exchange technique (IET) using a cation exchange resin was applied to determine the concentrations of Cd2+, Cu2+, and Pb2+. It was shown that the pH and the amount of calcium (Ca) in solutions affected the distribution of metal ions to the resin. In the synthetic solutions involving Cl, SO4, and citrate, the metal‐ligand complexes did not affect the measurement of free metal ions by the IET. In soil solutions, the concentrations of free ions were affected by solution pH, varying within 10−9–10−7 M for Cd, 10−9–10−6 M for Cu, and 10−9–10−7 M for Pb. The IET results were comparable to those measured by Cu‐ion selective electrode (ISE) and anodic stripping voltammetry (ASV). These findings suggest that the IET can be applied to soil solutions for metal speciation measurements. Keywords: Trace metalsspeciationsoil solution Acknowledgments We thank Hélène Lalande, Peter Campbell, Claude Fortin, John Luong, and Abdelkader Hilmi for their help with the various speciation techniques. The financial support from a doctoral scholarship from “Fonds québécois de la recherche sur la nature et les technologies” (formerly FCAR) Toxic Substance Research Initiative (TSRI), Health Canada, and the Natural Sciences and Engineering Research Council of Canada is greatly appreciated.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.003 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".