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+ Chemistry
+ Oxygen isotopes
+ Isotope analysis
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Lula Barnett

Can any one tell me how compound specific isotope analysis of...

Miguel Corazao  Follow

I do not quite understand your question but this is dating sediment chronology related question I do not think stable isotopes 13C and 15N will help you to date chronology your sediment samples.

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Barbara Davis  Follow

As Dr. Steele said above it depends on the compounds and specific isotope you are looking to analyze (13C, 15N, etc.). For volatile compounds the GC-C-IRMS is what you need, but for less volatile things like porphyrins you need an HPLC setup to do compound isolation/collection. Then you need an IRMS setup that can handle extremely low quantities of sample, for 13C there are a number of different ones out there but If you are looking for 15N numbers, those are tougher as there are only a handful of labs that have the capability to run compound specific nitrogen isotopes (Penn State, Harvard, and Syracuse off the top of my head) as it involves a fairly specific cryotrapping setup.

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Albert Donnay  Follow

I'm not quite sure exactly what you are asking.  Do you want to know what instrument is used or what specific extraction and analysis methods might be appropriate?
The answer to the first part is easy - you need access to gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS).  There are not that many around as the equipment is expensive and tricky to maintain.
The exact methods will depend on what kind of compounds you want to look at - alkanes, PAHs, lipids etc. 
Finally is always worth identifying exactly what you are trying to find out to see if GC-C-IRMS is really going to give you the answer you want.

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