The results of iron(II,III) and hardness determination in water samples
Sample 1 – Standard solution
| MET result | Certified laboratory result | |
| Hardness, mmol/L | 1.15 ± 0.15 MET-Hardness test kit, titrimetric determination | 1.15 ± 0.08 LVS ISO 6059:1984 |
| Iron(II,III), mg/L | 0.49 ± 0.08 MET-Fe(II,III) test kit, photometric determination | 0.47 ± 0.04 LVS ISO 6332:2000 |
Sample 2 – Tap water in Riga
| MET result | Certified laboratory result | |
| Hardness, mmol/L | 1.60 ± 0.15 MET-Hardness test kit, titrimetric determination | 1.67 ± 0.12 LVS ISO 6059:1984 |
| Iron(II,III), mg/L | 0.17± 0.02 MET-Fe(II,III) test kit, photometric determination | 0.14 ± 0.01 LVS ISO 6332:2000 |
Sample 3 – Natural water in Jurmala
| MET result | Certified laboratory result | |
| Hardness, mmol/L | 3.40 ± 0.30 MET-Hardness test kit, titrimetric determination | 3.69 ± 0.26 LVS ISO 6059:1984 |
| Iron(II,III), mg/L | 1.31 ± 0.22 MET-Fe(II,III) test kit, photometric determination | 1.30 ± 0.12 LVS ISO 6332:2000 |