| Heavy metals | CRM | Certified values (µg/g) | Measured values (µg/g) | Recovery (%) |
| Cu | Soil-5 | 77.1 ± 4.7 | 75.62 ± 5.0 | 99 |
|
| DOLT-3 | 31.2 ± 1.0 | 29.8 ± 2.7 | 96 |
| Zn | Soil-5 | 368.0 ± 8.20 | 362.9 ± 15.6 | 100 |
|
| DOLT-3 | 86.6 ± 2.4 | 83.8 ± 3.5 | 97 |
| Pb | Soil-5 | 129.0 ± 26.0 | 124.8 ± 22.0 | 97 |
|
| DOLT-3 | 0.32 ± 0.05 | 0.38 ± 0.09 | 109 |
| Cd | Soil-5 | 1.5 ± 0.0 | 1.56 ± 0.03 | 101 |
|
| DOLT-3 | 19.4 ± 0.6 | 20.5 ± 0.4 | 105 |
| Ni | Soil-5 | 13 ± 0.00 | 12.85 ± 1.02 | 107 |
|
| DOLT-3 | 2.72 ± 0.35 | 2.77 ± 0.74 | 101.8 |