Table 3.
A comparative study of the reagentless biosensor and Nessler method for NH4+ ion analysis in different river water samples containing spiked NH4+ ion concentrations from 10–30 mM.
| Sample | Concentration of NH4+ ion spiked in each sample (mM) | Concentration of NH4+ ion determined by biosensor (n = 3), (mM) | Concentration of NH4+ ion by Nessler method (n = 3), mM | Recovery (%) |
|---|---|---|---|---|
| Sample 1 | 10.00 | 10.29 ± 0.95 | 10.41 ± 0.79 | 102.9 |
| Sample 2 | 18.00 | 18.63 ± 1.05 | 18.20 ± 0.91 | 103.5 |
| Sample 3 | 22.00 | 21.56 ± 1.52 | 21.90 ± 0.76 | 98.0 |
| Sample 4 | 26.00 | 26.13 ± 0.32 | 26.10 ± 0.15 | 100.5 |
| Sample 5 | 30.00 | 29.01 ± 2.33 | 30.38 ± 1.20 | 96.7 |