Isotope Analysis Service

Welcome to the CSIRO Isotope Analysis Service, Adelaide, South Australia. 

The service provides stable isotope analyses for hydrological and environmental purposes. It also has a comprehensive capability for dating groundwater through the , CFC, SF₆ and Noble gas laboratories and analytical facilities for ²²²Rn and ²²⁶Ra.  The isotope laboratory has special expertise in groundwater hydrology. 

Established in 1984, the service now undertakes approximately 3000 analyses per year for over 100 customers, 20% of which are based outside Australia. 

The major strengths of this service are: 

• Commercial service established for over 25 years
• Laboratory established for 40 years
• Continuing analytical development 
• Reliable turnaround 
• Extensive collaboration with universities and Australian federal and state government departments 

Stable isotopes 

Deuterium (d²H), Oxygen-18 (d ¹⁸O) and Carbon-13(d ¹³C)

Deuterium and oxygen-18 compositions of water samples provide a useful tool for investigating hydrological processes in surface and groundwater systems. In groundwater, the ²H and ¹⁸O signature gives an indication of the climatic conditions under which recharge took place. In surface water/catchment studies, stable isotopes have been used to estimate retention times and the hydrologic response of catchments to rainfall. 

The Service also supports research work in which stable isotopes are used to identify the different sources of water taken up by plants.

d¹³C for carbonate material may indicate whether it is of marine or terrestrial origin while d¹³C for dissolved inorganic carbon (DIC), when used with ¹⁴C analysis, provides a methodology to correct groundwater ages for water-rock interaction. 

Please see the Information Sheet for sample collection and information for d²H and d¹⁸O analysis.  

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Carbon dating 

Established in 1976 primarily for dating water samples, the laboratory began commercial carbon dating services in 1984. An older benzene-based system was replaced by a procedure involving the direct absorption of CO₂ into Carbosorb for counting via a low level Quantulus Liquid Scintillation Counter (DA). This procedure proved to be a more reliable, cost effective alternative to benzene synthesis. In the late 1990s, carbon-14 analysis was also offered using Accelerator Mass Spectrometry (AMS). For a while, AMS analysis was considerably more expensive than the DA method and hence used mainly when there was limited amount of carbon available for analysis. However, over the years, the price differential between the two methods decreased and the DA line was officially closed in 2011.

Dissolved inorganic carbon from water samples requiring carbon-14 analysis are now precipitated and converted to CO₂ at the CLW laboratory and the CO₂ sent  to the Australian National University in Canberra for AMS analysis. A d¹³C analysis for each sample is provided free of charge with each carbon-14 analysis.

With extensive experience in radiocarbon analysis of groundwater samples from regional aquifers throughout Australia, the IAS is now the principal provider of this service in Australia and a major provider for the Asian-Pacific region. 

Please see the Information Sheet for sample collection and information for AMS ¹⁴C analysis.

Chlorofluorocarbon (CFC) and Sulfur Hexafluoride (SF₆) analysis 

The presence of man-made CFCs and SF₆ in the atmosphere for the last 50 years means that these compounds are now in groundwater in quantities that largely reflect the presence and proportions of recent recharge waters.

Measurement of CFC-11 and CFC-12 allows groundwater ages to be determined since the mid 1960s with a precision of approximately three years. However, since the 1990s, atmospheric CFC11 and CFC12 concentrations have levelled off and more recently have started to decrease.

This has meant that it is difficult to obtain an accurate CFC groundwater age using CFC concentrations for groundwater that recharged within the last decade or so. Atmospheric SF₆concentrations however, continue to rise and hence are not subject to this problem.

The specialised nature of sample collection for CFC and SF₆analysis means that this service requires special sampling equipment/bottles and hence prior arrangements need to be made with clients prior to sampling.

Please see the Information Sheet for sample collection and information for CFC analysis.  For SF₆, the laboratory follows the sampling protocol of the USGS [external link].

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²²²Rn and ²²⁶Ra 

²²²Rn and ²²⁶Ra form part of the decay chain for uranium bearing minerals. They are often found in higher concentrations in groundwater than in surface water because the groundwater usually has more contact with soil than the surface water. By utilising this, ²²²Rn and ²²⁶Ra are often used to identify areas of input of groundwater into streams and rivers. Determination of dissolved ²²²Rn and ²²⁶Ra in groundwater is reasonably simple, requiring only 14 ml water samples. The present detection limit, based on two standard deviations from background is 0.180 Becquerels per litre (1 Becquerel = 1 dist per sec). This method of radon analysis is called the Direct Method.

In 2006, staff at CLW developed a quick and easy method (PET method) for measurement  of ²²²Rn and ²²⁶Ra for samples having much lower concentrations. The limit of detection, based on two standard deviations above background for the PET and Direct methods is ~5 mBq/L for the sample count time usually employed at CLW (200 minutes).  The PET method has allowed much more accurate measurements of ²²²Rn and ²²⁶Ra concentrations in surface water samples and is used often in groundwater surface water interaction studies.

Please see the Information Sheet  for sample collection and information for ²²²Rn and ²²⁶Ra analysis.

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Service specifications 

Facilities 

• Three stable isotope gas ratio mass spectrometers 
• Two Wallac Quantulus Liquid Scintillation Counters 
• CFC analysis by purge and trap gas chromatography
• SF₆ analysis by equilibration and trap gas chromatography
• Automated equilibration system for ²H and ¹⁸O analysis of water
• Quadrupole mass spectrometer for Noble gas analysis.

Average turnaround

Precision and sensitivity 

The Service can detect isotope concentrations to the following level of precision: 

Sample requirements 

Prospective clients should note the following minimum amounts of sample material required by the laboratory for analysis. If it is not possible to collect enough material for analysis, please contact the laboratory prior to sampling to discuss alternative options. In any case, direct contact with the laboratory before submitting samples is essential to ensure appropriate procedure for sample collection and treatment.

Please do NOT add Mecuric Chloride to water when collecting samples as this causes problems with some analyses.   

* The amount of water required to provide sufficient carbon (as DIC) for ¹⁴C analysis is primarily a function of the pH and [HCO^-₃] of the water sample. Please ask laboratory staff to send an Information Sheet prior to sampling. 

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Price list 

Printable price list also available (PDF, 15 kB)

Plant and Soil Water

Soil Physical Chemical Analysis

*samples collected in triplicate in bottles supplied by CLW
**samples collected in special bottles supplied by CLW. We suggest noble gas analysis to determine excess air be measured on selected samples. Please discuss this with laboratory before sampling.
*** samples collected in copper tubes supplied by CLW. Please discuss this with laboratory before sampling.
**** samples collected in Ni diffusion cells supplied by CLW. Please discuss this with laboratory before sampling.
# price includes distillation to extract water for analysis
## price includes gravimetric water content 

All prices are in Australian dollars. Prices do not include GST. Please contact the laboratory if submitting samples from outside Australia in order to make arrangements for quarantine inspection. Please contact Fred Leaney or Megan LeFournour for further information. 

Staff 

Mr Fred Leaney Principal Research Scientist, general isotopic services 
Ms Megan LeFournour Senior Technical Officer, submission/reporting, stable isotope analyses
Ms Michelle Caputo Technical Officer, CFC, SF₆, ¹⁴C, ²²²Rn anlyses
Mr Todd Maddern Senior Technical Officer, Noble gas analyses, instrumentation

For further information contact: 
Mr Fred Leaney 
CSIRO Land and Water
Private Bag No. 2
Glen Osmond SA 5064
Australia
tel: +61-8-8303 8728
fax: +61-8-8303 8750
E-mail: Fred Leaney

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