Cl separation from silicates and carbonates
"Ten million atoms isn't cool, you know what's cool? Ten thousand atoms" *
COSMOGENIC ISOTOPE PREPARATION FACILITIES
The Cosmogenic Nuclide Laboratories at the University of Washington are used to prepare samples for ultra low level isotopic analysis by Accelerator Mass Spectrometry (AMS). We are set up to cover all the necessary procedures from rock crushing and mineral separation through to loading of accelerator cathodes. We can prepare samples for Be-10, Al-26 and Cl-36 analysis, starting from separated quartz, calcite, feldspar and other minerals, as well as whole-rocks, soils, sediments, natural waters and glacier ice. Samples for Cl-36 and trace chloride measurements are processed in a dedicated clean lab, isolated from hydrochloric acid vapor. Low-level Be-10 and Al-26 extractions from quartz are carried out under clean conditions in a separate lab from soil and sediment chemistry. The low-level labs are equipped wih HEPA-filtered laminar downflow cabinets to minimise particulate contamination. Full procedural blanks are typically 5,000 - 20,000 atoms for Be-10, 20,000 atoms for Al-26, and 5000 - 10,000 atoms for Cl-36.
LABORATORY PROCEDURES
The files linked to this page include the procedures we use to extract and purify Be, Al and Cl for AMS and related analyses. They have been developed, tested and upgraded over several years, on thousands of samples, and we believe they work well. Try them out and see for yourself. We'd be interested to receive comments and suggestions, especially any that correct, improve or simplify the procedures. We modify them occasionally, and will try to keep descriptions on this site up to date.
Some files contain a reference to a published description of the method. If you adopt one of these methods (which presumably means that it (a) worked, and (b) helped with a long-standing problem, or (c) rescued unusual or misbehaving samples) please cite the reference.
Disclaimer: These methods are intended for scientists trained in analytical chemistry, who are able to understand the procedures and apply them safely. Some of these methods involve toxic, corrosive, carcinogenic or otherwise dangerous reagents. You must not attempt to use these procedures unless you have a clear understanding of the hazards, safe handling, legal regulation and responsible disposal of the required reagents, particularly hydrofluoric acid, perchloric acid and beryllium compounds.
Users should also realise that we cannot guarantee these methods in any way. Procedures may need to be adapted to specific laboratory conditions or modified to meet the requirements of specific AMS facilities. Though these methods are robust, they cannot be expected to cope with the infinite variety of geological samples. It is up to you, the user, to anticipate problematic samples and adapt the procedures accordingly. We strongly recommend practicing on blanks or test solutions before using these methods on valued samples.