Department of Biological Sciences

Waikato Stable Isotope Unit

Sample Preparation

Samples are normally submitted for analysis as very finely ground (‹200 µm) oven dried material. Processing to this stage is by the customer, and our charges are based on this assumption. Normal laboratory grinding procedures are usually sufficient to ensure good precision in 5-10 mg samples. In many instances, small samples of dry material can be ground in a mortar and pestle. Some materials such as dry fish tissue, can be readily ground under liquid nitrogen. For larger quantities of material, a mechanical grinder is more suitable, and for variable material, a ball mill is best. The homogeneity of the sample is one of the major variables in the precision of the analysis.

Samples should be packed in small plastic or glass vials and labelled carefully. We are happy to return unused material to you at your cost. Liquid samples can be processed, but must be reduced to a small volume (50 µL). Gaseous samples, such as breath, can also be processed.