Table 3.
Concentrations of As and Cd determined in SRM 3280 by ICP-MS along with residual solution concentrations of interfering matrix elements across each coprecipitation step. Values are mean ± standard deviation of five separate preparations (n = 5). Values in parenthesis indicate per cent deviation (inaccuracy) from the certified value of As and Cd.
| Analyte | Certified value (ng g-1) |
Step 1 | Step 2 | Step 3 | |
|---|---|---|---|---|---|
| 75As (ng g−1) | 132 ± 44 | 182 ± 22 | 141 ± 18 | 112 ± 37 | |
| (+38%) | (+7%) | (−15%) | |||
| 110Cd (ng g−1) | 116 ± 14 | 77 ± 9 | 76 ± 5 | ||
| 80.2 ± 0.9 | (+45%) | (−4%) | (−5%) | ||
| 111Cd (ng g−1) | 118 ± 15 | 78 ± 6 | 79 ± 5 | ||
| (+48%) | (−2%) | (−2%) | |||
| 114Cd (ng g−1) | 125 ± 14 | 88 ± 7 | 78 ± 7 | ||
| (+56%) | (+10%) | (−2%) | |||
| Residual concentration of the matrix and interfering elements | |||||
| Mo (µg mL−1) | 1.7 ± 0.1 | 0.42 ± 0.05 | 0.37 ± 0.05 | ||
| Sn (µg mL−1) | 0.10 ± 0.01 | 0.02 ± 0.005 | 0.02 ± 0.003 | ||
| Mg (µg mL−1) | 2331 ± 145 | 1224 ± 159 | 21 ± 5 | ||
| P (µg mL−1) | 2921 ± 280 | 2133 ± 190 | 1451 ± 110 | ||
| Ca (µg mL−1) | 3688 ± 262 | 2358 ± 200 | 9 ± 3 | ||
| K (µg mL−1) | 461± 28 | 80 ± 8 | 55 ± 7 | ||
| Na (µg mL−1) | 4 ± 1 | nd | nd | ||
nd = not determined