Please send your samples along with a order form and sample weight and sample names as an Excel-sheet

Solid matter ¹⁵N or ¹³C-determination following elemental analysis

• Samples should be homogeneous (finely ground) and dry. No homogenisation is necessary, if the whole sample is combusted (e.g. analysis of whole animals like ants, collembola, or others).
  While homogenizing care should be taken not to lose particilar fractions of the sample (e.g. lipid fraction during milling of animal samples, which tends to stick on the mortar).


• Natural abundance and labelled samples must be kept apart and delivered in separate sample wells.


• For accurate analysis, expected amounts and isotope enrichments are needed.


• Samples weighed into tin cups should be delivered in 96 well culture trays. For each uniquely(!) labelled tray a data file and printout with sample names and weights should be provided. Please make sure the culture wells are tightly closed to avoid mixing up of samples.


• Tin cups (use small cups) should be formed to small balls (flat cups get stuck in the autosampler)


• Tin cups should be tightly sealed (straying samples will lead to crosscontaminations in the autosampler)


• Each customer should prepare his own standard of a substance similar to the analysed samples. This standard should be run after every 20 samples and will monitor reproducibility of measurement.


• For an analysis, amounts of 50 µg N or 100 µg C are sufficient. However, it may be more appropriate to choose higher sample weights for inhomogeneous substances. Very small samples or samples with very low C or N content can be analysed with amounts of 20µg C or N.

If sample weights exceed 100mg, please contact lab staff.

• The amount of C and/or N should not differ too much between samples of one batch.

Prepraration of water samples for 18O and/or 2H analysis

• samples should be free of particulate matter (filter over 0,45µm. Attention: Do not use vacuum, this may lead to fractionation


• Samples should not be poisoned or acidified.


• Samples should be sent in small containers with only little headspace. Use glass vials to avoid evaporation and fractionation.