Table 2. Mean soil concentrations of thiamethoxam and imidacloprid (±standard error of the mean) as determined by HPLC1 in 2014.
| Site (planting date) | Sampling date (days post planting) | Thiamethoxam (ng/g) | Imidacloprid (ng/g) |
|---|---|---|---|
| Chillicothe (5/19) | 6/4 (15) | 20 ± 8.8 | 35 ± 13 |
| 6/19 (28) | 33 ± 17 | 28 ± 12 | |
| Lamesa (5/17) | 6/10 (23) | 65 ± 29 | 162 ± 144 |
| 9/29 (134) | 4.9 ± 0.5 | 5.2 ± 4.0 | |
| Wall (5/23) | 6/18 (25) | 14 ± 5.2 | 16 ± 2.1 |
| 9/29 (128) | 9.4 ± 1.2 | 8.2 ± 2.5 | |
| Halfway (5/6) | 10/1 (147) | 20 ± 4.5 | 98 ± 47 |
| Kress (5/13) | 10/1 (140) | 12 ± 1.2 | 38 ± 34 |
Notes:
1
The MDLs for thiamethoxam and imidacloprid in soil extracts were 1.0 and 0.5 ng/g, respectively.