Table 2.
Predicted speciation of Cd in various tissues of Carpobrotus rossii grown for 10 d in solutions with the same Cd2+ activity (10.9 µm), as calculated using linear combination fitting of the K-edge XANES spectra (Experiment 1)
| Treatment | R factor | Cd–OH (%) | Cd–S (%) | Cd–Cl (%) | ||
|---|---|---|---|---|---|---|
| Code | Salt | Cd (µm) | ||||
| Root | ||||||
| T5 | 0 | 15 | 0.001316 | 23.2 (0.9) | 76.8 (2.7) | – |
| T9 | 25 mm NaNO3 | 22 | 0.001027 | 15.7 (0.8) | 84.3 (2.5) | – |
| T10 | 12.5 mm Na2SO4 | 42 | 0.000943 | 29.8 (0.8) | 70.2 (2.6) | – |
| T11 | 25 mm NaCl | 50 | 0.001235 | 19.2 (0.9) | 80.8 (2.8) | – |
| Xylem sap | ||||||
| T5 | 0 | 15 | 0.000357 | 89.3 (1.1) | 10.7 (1.8) | – |
| T9 | 25 mm NaNO3 | 22 | 0.000816 | 93.6 (3.3) | 6.4 (0.8) | – |
| T10 | 12.5 mm Na2SO4 | 42 | 0.000335 | 91.9 (5.2) | 8.1 (0.5) | – |
| T11 | 25 mm NaCl | 50 | 0.000101 | 24.9 (3.4) | – | 75.1 (0.7) |
| Stem | ||||||
| T5 | 0 | 15 | 0.000418 | 38.1 (0.5) | 61.9 (1.4) | – |
| T9 | 25 mm NaNO3 | 22 | 0.000585 | 38.8 (3.3) | 61.2 (0.6) | – |
| T10 | 12.5 mm Na2SO4 | 42 | 0.000369 | 30.2 (0.5) | 69.8 (2.1) | – |
| T11 | 25 mm NaCl | 50 | 0.000490 | 21.4 (0.6) | 78.6 (2.0) | – |
| Leaf | ||||||
| T5 | 0 | 15 | 0.000384 | 11.7 (0.5) | 88.3 (2.1) | – |
| T9 | 25 mm NaNO3 | 22 | 0.000927 | 11.8 (1.2) | 88.2 (0.8) | – |
| T10 | 12.5 mm Na2SO4 | 42 | 0.001401 | 17.3 (1.4) | 82.7 (1.0) | – |
| T11 | 25 mm NaCl | 50 | 0.000748 | 5.7 (0.7) | 94.3 (1.0) | – |
Values in parentheses show percentage variation in calculated values.
Goodness of fit is indicated by the R factor [= Σi (experiment – fit)2⁄Σi (experimental)2] where the sums are over the data points in the fitting region.