C/N Tips

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Biogeochemical Stable Isotope Facility

School of Ocean and Earth Science and Technology

Popp Lab

To contact us:

Lab Phone: 808-956-5362

Fax: 808-956-5512

Lab Email: isobiogeo@soest.hawaii.edu


Important tips for preparing samples for EA analysis

Be sure to dry completely...water can affect our instrument, and the resulting data won't be reliable.

Samples must be ground to a fine, homogeneous powder.  This ensures that the sampled aliquot, which can often be small (i.e. tenths of a milligram), will be a complete representation of the entire sample.  

Try your best to constrain the carbon and nitrogen estimates...this ensures that when you weigh your sample or take your sample, you will have an optimal amount of carbon and nitrogen.

We must be notified for special procedures such as acidification of samples (filters or solid samples).

If acidifying samples, then be sure to use silver capsules.

Nicely wrapped samples will be tight and secure. Avoid edges sticking out or flat configurations, as they can get caught in the autosampler and create serious problems (please see pictures for examples). Packed filters should be dense and fully contained in the tin foil wrapper. All samples should fit loosely within the wells of the plate. If your samples are too large to fit in wells of a 96-well plate, then a plate with larger wells should be used. Do not submit plates with samples stuck in the wells.


Please tell us if the sample is isotopically labeled!

Bad filters, in more detail:

How your filters samples should fit in a 96-well plate:

How your filters samples should NOT fit in a 96-well plate: