Table 1.
δ15N values of the tryptophan (lab standard) and USGS40 (international standard): mean and standard deviation for each day
| Tryptophan | USGS40 | ||
|---|---|---|---|
| mean | sd | mean | sd |
| –2.71 | 0.07 | –4.83 | 0.13 |
| –2.07 | 0.03 | –4.09 | 0.07 |
| –2.23 | 0.05 | –4.21 | 0.24 |
| –2.07 | 0.03 | –4.23 | 0.25 |
| –2.1 | 0.08 | –4.23 | 0.27 |
| –2.02 | 0.08 | –4.06 | 0.06 |
| –2.11 | 0.06 | –4.16 | 0.14 |
| –2.07 | 0.03 | –4.23 | 0.25 |
| –2.07 | 0.03 | –4.09 | 0.07 |
| –1.98 | 0.17 | –3.93 | 0.17 |
| –2.58 | 0.13 | –4.58 | 0.04 |
| –2.64 | 0.1 | –4.71 | 0.14 |
| –2.23 | 0.05 | –4.21 | 0.24 |
| –2.1 | 0.08 | –4.23 | 0.27 |
n = 4 for both the standards for each day.
Measurements are independent of any correction calculations.