STABLE ISOTOPE LABORATORY Sample Size Requirements

For those of you weighing your own samples, PLEASE note the maximum sample sizes!
Not all IRMS laboratories are the same, and mass spectrometers are tuned differently.
We tune for maximum sensitivity, so we require smaller sample sizes.

Minimum Sample Sizes Needed for Analysis

Isotopes

Sample Matrix
Volume/Mass

Doubly-labeled Water (metabolic studies):

18O
body fluid
200ul*
HD
body fluid
10ul*

Other enriched water studies

18O
plant or soil fluid
200ul*
HD
plant or soil fluid
10ul*

Natural Abundance Fluid/Water:

18O
fluid
200ul
HD
fluid
10ul

C and N

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

water for NH4, NO3
500-1000 ml

water samples for DIC
200 ml

blood for bicarbonate
1 ml

S dried animal tissue
50 mg

dried plant tissue
100 mg

sediment and soil
100 mg

water samples
1 liter

* a total of 210 ul of fluid is needed. 18O for smaller samples is under development. For one analysis, 100 ul 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 umoles
POM filters
call
Small organic samples
call
Maximum amount of nitrogen per sample
210 ug
Maximum amount of carbon per sample
1032 ug
**Please contact lab manager to confirm soil size requirements.
We are not responsible for lost data due to incorrectly weighed samples.

 

 

For further information: