| Sample quantity (µg) | Amount of added RS (µg) | Total amount recovered (µg) | Recovery rate (%) | |
| 50 | 40 | 8.930 | 98.90 | |
| 50 | 40 | 8.947 |
| |
| 50 | 50 | 9.915 | 100.000 | |
| 50 | 50 | 10.085 |
| |
| 50 | 60 | 10.960 | 100.450 | |
| 50 | 60 | 11.090 |
| |