VIRIS - Vienna Isotope Research Investigations and Surveys

Aim of this project is the implementation and development of a new and challenging field of research in Austrian: the high precision measurement of isotope ratios by using multi collector ICP-MS (MC-ICP-MS). This multidisciplinary project is conducted at the University of Natural Resources and Applied Life Sciences in collaboration with the University of Vienna and the Museum of Natural History, Vienna. The increasing number of applications opens up new doors to natural and applied science which were not accessible before. A large variety of isotopic ratios can be measured with highest instrumental precision. Additionally, modern instruments allow high mass resolution in order to investigate also isotopic systems suffering from isobaric spectral overlaps in common ICP-MS systems. A diligent assessment of the measurement protocol is a prerequisite to avoid that scientific, conclusions are drawn from analytical artefacts. Therefore, an important fundamental goal of the project is the understanding of ionic processes and isotopic effects. The technological development will also include the development of an on-line matrix separation or the use of a reaction/collision cell in order to study the direct suppression of spectral interferences. The fundamental research will be directly transferred to three main pillars of applied research: the development of multi-isotopic patterns for validation of food authenticity: In 2005, an new legislation will be implemented in the EU, which aims at the traceability process along the production chain of food and feed in order to guarantee public health and consumer protection. One promising approach is the establishment of multi-isotopic pattern. In-situ LA-MC-ICPMS U-Th-Pb geochronology and REE geochemistry and geo-thermo barometry of phosphates in metamorphic and sedimentary rocks: The overall goal is to establish xenotime thermo chronometry as a geochronological-petrological tool. Only in-situ LA-MC-ICP-MS dating provides the necessary textural control and analytical sensitivity for successful dating. The study of human Neolithic migration into Europe and characterization of prehistoric skeletal remains using Sr isotope ratios: Unique Neolithic remains as well as Neanderthal teeth, which could not be analysed ever before, will be studied in combination with laser ablation. The results will shed light on a so far unknown chapter of human history. The long term sustainability of the project is underlined by a variety of international contacts and planned follow- up projects. It is the exact time for this equipment to be installed and made available in Austria in order to enhance the Austrian role in international research.

The investigation of isotopes has gained increased importance within the last years in science. Isotopes are atoms of one element with the same chemical properties only different in its number of neutrons in the nucleus. They are a result of the formation of our universe. Most of the natural occurring isotopes are stable whereas some of them (e.g. U and Th isotopes) decay emitting radioactive radiation. The project VIRIS investigates naturally occurring stable isotopes of elements which have gained increasing importance but where still limited information was available. The main isotopic systems under investigation were boron, sulfur, strontium, lead and uranium. The isotopic composition leads to a fingerprint, which is specific of a region and can be used in order to determine e.g. the provenance of objects and goods. In order to read this information, a specific mass spectrometer (a multi-collector inductively coupled plasma mass spectrometer) was used. This instrument was the first of its kind in Austria at the begin of the START project. The instrument was coupled with a laser ablations system, which allowed for the investigation of solid objects with high spatial resolution in the micrometer range. This combination was e.g. used to determine the isotopic composition of Pb along a single hair of Beethoven to determine the origin of the contaminant or the uranium isotopic composition of m sized single particles in nuclear forensics. The latter project was conducted in collaboration with the IAEA, where the method showed its potential to determine illegal nuclear activities. Moreover, the dating of smallest minerals evolved as challenging field in geology. The investigated elements (above all Sr) deliver an important source of information to determine the origin and provenance of food via their isotopic composition. E.g. the asparagus from the Marchfeld or the Hungarian paprika could be identified by assigning a unique fingerprint. As another example, a single green coffee bean could be traced back to its farm of origin by using the unique isotopic fingerprint. This isotopic pattern is further incorporated via the food chain into animals and humans. Especially the element strontium can be used to study human and animal migration. In this context, Sr was applied as method to study early human migration by analyzing Sr isotopes in bony tissues. In collaboration with the Museum of Natural History Vienna, unique insights in the early life of human settlements in Austria could be gained. Moreover, the isotopic information is incorporated e.g. in fish hard parts such as otoliths (ear stones of a teleost fish) time resolved. This information tells comparable to a tree ring the life story of a fish and give information about the migration behavior or the provenance if fish is used as food stuff. Very recent research deals with the application of enriched non toxic stable isotopes to create unique isotopic marker in natural systems.