Stable isotope analyses

The Laboratory of Chronology conducts active stable isotope research, with particular expertise in isotopic analyses of skeletal samples and tree rings. We are one of a handful laboratories worldwide providing the extraction and δ18O analysis of the phosphate component of skeletal bioapatite. Our services are available to both internal and external customers.
Isotopic archives of our environment and life

The Earth and everything on it is made up of isotopes. The ratios of stable isotopes in different materials record information about their origins, circumstances during formation, as well as various processes having affected them ever since. They reveal stories of e.g. past climatic changes, the diets of ancient peoples and help understand the connectedness of all life.

Routine services

We provide a range of stable isotope analytical services, first and foremost for scientific research projects. Time permitting, analytical services are available also for non-academic customers. NOTE! We do not analyze isotopically labeled samples.

Isotope analyses

Routine pretreatments and extractions

  • microbalance weighing into analysis
  • sample drying (warm/ freeze-drying)
  • sample homogenization
  • carbonate removal/acid fumigation
  • cellulose extraction from wood chips 
  • collagen extraction from bone and dentine
  • phosphate extraction from skeletal samples

If you’re interested in a service not listed above, please contact us at and describe your project. We can develop custom procedures, but these are usually restricted to larger collaborative research projects.

Pricing and turnaround times

The price list for stable isotope services applies (VAT 0%) for samples weighed, sealed and delivered to the laboratory in the prescribed analytical vial ready for IRMS analysis

The standard turnaround time for routine services when received ready for measurement is 1-2 months. Please ask for possibilities of expedited service at additional cost.

Submitting samples for analysis

Before submitting samples, contact us at, Please, don’t send or deliver samples to the laboratory before receiving an ‘OK’ from our staff. 

To help us serve you effectively, please include the following information in your email:

  • Desired isotope analysis/analyses.
  • Sample material. Give as much detail as possible, including any possible prior treatments.
  • Number of samples and desired replication (analysis in duplicate/triplicate). If you are interested in several different isotope analyses, give sample/replication numbers for each analysis separately.
  • Additional services required (weighing, pretreatments, extractions). If you request weighing into analysis as a service for soils, sediments, unusual materials, or ẟ15N of plants/fungi/lichen, please include the expected (measured or estimated) weight-% of the element of interest in your samples.

Samples can be mailed (postal service) to: 
Isotope analyses, Laboratory of Chronology
P.O.Box 64, 00014 University of Helsinki, FINLAND

For courier services (Fedex, DHL etc. ) use the street address:
Isotope analyses, Laboratory of Chronology
Gustaf Hällströmin katu 2, 00560 Helsinki, FINLAND

You can also hand deliver your samples to our premises at the Kumpula Campus (Physicum building) of the University of Helsinki

Preparing samples

More information on preparing your samples, and instructions for weighing and encapsulation for analysis is available via the links for each respective analysis type above, under Routine Services. 


We perform stable isotope analyses on two isotope ratio mass spectrometer (IRMS) systems, both provided by Thermo Scientific. A more detailed list of our instrumentation is available through the link below.


Analytical quality is assured and demonstrated according to the best practice recommendations of the field through application of internationally acknowledged procedures and reference materials. The QA/QC practices and typical measurement precision for each respective analysis type is available via the links above, under Routine Services.