Sample Size Requirements
Not all IRMS laboratories are the same, and mass spectrometers are tuned differently.
We tune for maximum sensitivity, so we require smaller sample sizes for preloaded samples. Amounts listed where the lab will load the samples allow us to run duplicates and rerun samples if necessary. All remaining material will be returned to the submitter.
Minimum Sample Sizes Needed for Analysis
|
Isotopes |
||
| Doubly-labeled Water (metabolic studies): | ||
|
body fluid |
200 μl* |
|
body fluid |
10 μl* |
| Other enriched water studies | ||
|
plant or soil fluid |
200 μl* |
|
plant or soil fluid |
200 μl* |
| Natural Abundance Fluid/Water: | ||
|
fluid |
200 μl |
|
fluid |
200 μl |
|
plant tissue |
5-10 mg (C) |
30-50 mg (N) |
||
dried animal tissue |
2-5 mg (C) |
|
2-10 mg (N) |
||
sediment (marine, freshwater) |
2-10 mg(C) |
|
50 mg (N) |
||
soil (varies with %C) |
20-1000 mg |
|
| 15N | water for NH4, NO3 |
500-1000 ml |
| 13C | water samples for DIC |
200 ml |
| 13C | blood for bicarbonate |
1 ml |
| S | S dried animal tissue |
50 mg |
dried plant tissue |
100 mg |
|
sediment and soil |
100 mg |
|
water samples |
1 liter |
* a total of 400 μl of fluid is needed. 18O for smaller samples is under development. For one analysis, 100 μl is currently
required.
Preloaded Sample Sizes
|
Material
|
Amount
|
|
Plant material for C and N
|
2 mg
|
| Animal material for C and N |
1 mg
|
| Soils/sediments (will vary with %OM)** |
2-14 mg
|
| DIN filters (N on filters) |
2-10 μmoles
|
| POM filters |
call
|
| Small organic samples |
call
|
| Maximum amount of nitrogen per sample |
210 μg
|
| Maximum amount of carbon per sample |
1032 μg
|
| **Please contact lab manager to confirm soil size requirements. |
We are not responsible for lost data due to incorrectly weighed samples.
|