Table 3.
Precision and recovery measurements for glyphosate and AMPA in NanoPure water, hard water, and EDTA-amended hard water
| NanoPure water | Hard water | EDTA-amended hard water | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Concentration | Avg. calculated amount (μg L−1) | RSDa (%) | Avg. recovery (%) | Avg. calculated amount (μg L−1) | RSD (%) | Avg. recovery (%) | Avg. calculated amount (μg L−1) | RSD (%) | Avg. recovery (%) | |
| Glyphosate | 1 μg L−1 | 0.997 | 7 | 99.7 | 1.1 | 20 | 111 | 0.99 | 10 | 98.5 |
| 5 μg L−1 | 5.1 | 20 | 101 | 4.9 | 10 | 97.5 | 5.1 | 20 | 102 | |
| 10 μg L−1 | 10.1 | 10 | 101 | 10.3 | 20 | 103 | 9.9 | 10 | 99.0 | |
| AMPA | 1 μg L−1 | 0.88 | 4 | 88.1 | 0.84 | 10 | 84.4 | 0.73 | 9 | 72.9 |
| 5 μg L−1 | 4.99 | 9 | 99.8 | 4.8 | 20 | 96.6 | 4.9 | 9 | 98.1 | |
| 10 μg L−1 | 9.9 | 6 | 98.9 | 9.9 | 30 | 99.1 | 10.1 | 8 | 102 | |
a
RSD values represent instrument precision determined via triplicate measurements of samples with known spiked concentrations of glyphosate and AMPA