Rapid determination of strontium radionuclides in plants, fodder and foodstuffs
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D. Tait
Abstract
The fission yield, the transfer factors in the food chain and the dose coefficient are large for the nuclear fission product Sr-90. The surveillance of Sr-90 in the food chain is therefore important in precautionary radiation protection and in assessing the radiation dose to the public especially after a nuclear incident. Prior to analysis, as it is a pure β-emitter, Sr must be separated from the sample by procedures which, for complex organic samples, are lengthy, laborious and dependent on operator skill. Ubiquitous natural radionuclides and short-lived fission products in samples contaminated with fresh fallout may interfere. Here we describe a fast, reproducible and effficient method for extracting Sr from grass, clover, maize, wholemeal rye, baby food, and total diet. The method depends on obtaining an ash free of traces of organic interferences. Sr may be separated from a dilute nitric acid leachate of such ash with a solution of dicyclohexyl-18-crown-6 in chloroform. Interfering radionuclides are removed with a special manganese (IV) oxide (active, precipitated from Merck). Sr is precipitated as carbonate then dispersed in a cocktail for liquid scintillation spectrometry. This allows simultaneous counting of Sr-89 (a short-lived β-emitter in fresh fallout) and Sr-90. The chemical yields of Sr determined with the gamma-emitting Sr-85 tracer are reproducible and greater than 75 % in all cases. The sample ashing requires 18 h and the extraction 4.0 to 4.5 h. Thus, a duplicate analysis may be completed within 2 days of receipt of the sample.
Kurzfassung
Die Spaltausbeute, die Transferfaktoren in die Nahrungskette und der Dosisfaktor des Spaltprodukts Sr-90 sind relativ groß. Daher ist die Überwachung der Sr-90-Aktivität in der Nahrungskette eine wichtige Maßnahme beim vorsorgenden Strahlenschutz und bei der Ermittlung der Strahlenexposition der Bevölkerung nach einem nuklearen Ereignis. Da Sr-90 ein reiner β-Strahler ist, erfordert die Analyse die zeitaufwändige und arbeitsintensive Abtrennung des Sr aus der Probe durch erfahrenes Laborpersonal. Die Analyse wird durch ubiquitäre natürliche Radionuklide und, nach nuklearen Ereignissen, kurzlebige Spaltprodukte gestört. Hier wird eine schnelle, reproduzierbare und effiziente Methode für die Abtrennung des Sr aus Gras, Klee, Mais, Roggen, Babynahrung und Gesamtnahrung beschrieben. Als Ausgangsmaterial ist eine von organischen Resten freie Asche der Probe erforderlich. Das Sr wird aus einem salpetersauren Extrakt der Asche mit dem Kronenether Dicyclohexyl-18-Krone-6 in Chloroform radiochemisch abgetrennt. Eventuell störende Radionuklide werden durch Kontakt mit einer speziellen Form des Mangan(IV)oxids (aktiv, gefällt, von der Fa. Merck) entfernt. Sr wird als Strontiumcarbonat gefällt, dann in einem Flüssigszintillationscocktail dispergiert. Die anschließende Messung mit Flüssigkeitsszintillationsspektrometrie ermöglicht (gegebenenfalls) die simultane Bestimmung des Sr-89 – eines kurzlebigen β-Strahlers im frischem Fallout – und Sr-90. Die mit Hilfe des gammastrahlenden Tracers Sr-85 ermittelten chemischen Ausbeuten des Sr sind reproduzierbar und betragen bei allen Probenarten mindestens 75 %. Die Dauer der Probenveraschung sowie der radiochemischen Abtrennung betragen 18 Stunden bzw. 4,0 bis 4,5 Stunden. Daher kann mit diesem Verfahren eine Doppelanalyse innerhalb von 2 Tagen nach der Annahme der Probe durchgeführt werden.
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© 2007, Carl Hanser Verlag, München
Articles in the same Issue
- Contents/Inhalt
- Contents
- Summaries/Kurzfassungen
- Summaries
- Editorial
- Environmental monitoring in the case of a radiological event
- Technical Contributions/Fachbeiträge
- The revised program for measurements in intense operation mode according to AVV-IMIS
- Early emergency response by means of dispersion forecasting – emergency management of the Deutscher Wetterdienst in the context of national and international agreements
- Improvement, extension and integration of operational Decision Support Systems for nuclear emergency management (DSSNET)
- European approach to nuclear and radiological emergency management and rehabilitation strategies (EURANOS)
- Bilateral information and data exchange in case of nuclear emergencies in the German-Dutch border region
- Implementation of decision support systems in Austria
- Source term assessment as a basis for protective measures for the population in case of a nuclear accident in a nuclear power plant with radiological consequences
- Characterization of dose rate instruments for environmental radiation monitoring
- Rapid determination of strontium radionuclides in plants, fodder and foodstuffs
- Longitudinal dispersion of radioactive substances in Federal waterways
- Fast online system for forecasting environmental impact during an incident
- Harnessing monitoring measurements in urban environments for decision making after nuclear accidents
- Correction of deposition predictions with data assimilation
- Potentials and limits of electronic situation displays
- Requirements of emergency control managements on data and information for assessment of the radiological situation in case of a severe accident in a nuclear power plant
- deNIS IIplus – computer-assisted crisis management system
- Iodine Prophylaxis following nuclear accidents – a concept how to distribute potassium-iodide tablets out of the central stocks in the event of an accident
Articles in the same Issue
- Contents/Inhalt
- Contents
- Summaries/Kurzfassungen
- Summaries
- Editorial
- Environmental monitoring in the case of a radiological event
- Technical Contributions/Fachbeiträge
- The revised program for measurements in intense operation mode according to AVV-IMIS
- Early emergency response by means of dispersion forecasting – emergency management of the Deutscher Wetterdienst in the context of national and international agreements
- Improvement, extension and integration of operational Decision Support Systems for nuclear emergency management (DSSNET)
- European approach to nuclear and radiological emergency management and rehabilitation strategies (EURANOS)
- Bilateral information and data exchange in case of nuclear emergencies in the German-Dutch border region
- Implementation of decision support systems in Austria
- Source term assessment as a basis for protective measures for the population in case of a nuclear accident in a nuclear power plant with radiological consequences
- Characterization of dose rate instruments for environmental radiation monitoring
- Rapid determination of strontium radionuclides in plants, fodder and foodstuffs
- Longitudinal dispersion of radioactive substances in Federal waterways
- Fast online system for forecasting environmental impact during an incident
- Harnessing monitoring measurements in urban environments for decision making after nuclear accidents
- Correction of deposition predictions with data assimilation
- Potentials and limits of electronic situation displays
- Requirements of emergency control managements on data and information for assessment of the radiological situation in case of a severe accident in a nuclear power plant
- deNIS IIplus – computer-assisted crisis management system
- Iodine Prophylaxis following nuclear accidents – a concept how to distribute potassium-iodide tablets out of the central stocks in the event of an accident
