| Parameter | Proficiency testing item M179A | Uncertainty | Proficiency testing item M179B | Uncertainty | Unit |
| Aluminium | 50.7 | 0.3 | 47.9 | 0.3 | µg/L |
| Antimony | 0.595 | 0.016 | 1.596 | 0.017 | µg/L |
| Arsenic | 1.910 | 0.015 | 0.72 | 0.02 | µg/L |
| Barium | 42.19 | 0.17 | 27.16 | 0.13 | µg/L |
| Lead | 5.64 | 0.14 | 3.65 | 0.07 | µg/L |
| Cadmium | 0.913 | 0.010 | 0.301 | 0.005 | µg/L |
| Chromium | 2.549 | 0.018 | 5.05 | 0.03 | µg/L |
| Iron | 75.9 | 0.3 | 25.52 | 0.17 | µg/L |
| Copper | 1.63 | 0.03 | 7.08 | 0.05 | µg/L |
| Manganese | 55.9 | 0.2 | 38.40 | 0.18 | µg/L |
| Molydenum | 2.32 | 0.04 | 6.47 | 0.06 | µg/L |
| Nickel | 2.01 | 0.03 | 5.64 | 0.04 | µg/L |
| Selenium | 0.76 | 0.03 | 2.12 | 0.05 | µg/L |
| Strontium | 465 | 4 | 565 | 5 | µg/L |
| Uranium | 4.18 | 0.03 | 3.10 | 0.03 | µg/L |
| Zinc | 11.1 | 0.7 | 29.5 | 0.9 | µg/L |
| Tin | 1.10 | 0.02 | 1.79 | 0.02 | µg/L |