| Milligrams of dried material to be weighed per sample | %N of sample | Micrograms of N needed per sample for isotope analysis | Possible sample types |
|---|---|---|---|
| 60.000 | 0.1% | 60 | soil |
| 12.000 | 0.5% | 60 | soil |
| 4.000 to 6.000 | 1.5% | 60 | decaying plant litter |
| 3.000 to 4.000 | 3.0% | 60 | fresh leaves, algae |
| 2.000 to 3.000 | 5.0% | 60 | legumes |
| 0.600 to 1.200 | 10.0% | 60 | all animals |
| 0.300 | 20.0% | 60 | ammonium salts |
| 0.150 | 40.0% | 60 | urea |