Samples | Element | Added (μg/L)a | Found (μg/L)b | Relative error, % |
---|---|---|---|---|
Tap water | Cd | – | N.D | – |
10 | 9.5 ± 0.2 | − 5 | ||
Cu | – | 12.3 ± 0.4 | – | |
10 | 20.6 ± 0.5 | − 8 | ||
Pb | – | N.D | – | |
10 | 9.4 ± 0.3 | − 6 | ||
River water | Cd | – | N.D | – |
10 | 9.3 ± 0.3 | − 7 | ||
Cu | – | 20.4 ± 0.6 | – | |
10 | 28.7 ± 0.7 | − 6 | ||
Pb | – | N.D | – | |
10 | 9.2 ± 0.2 | − 8 |