Organic molecule C14 dating sample preparation system and method

Abstract

The invention relates to the field of scientific research and in particular relates to an organic molecule C14 dating sample preparation system and method. The method comprises the following steps: filling an organic molecule sample into a quartz tube in a vacuumizing environment, adding copper oxide to serve as an oxidizing agent, carrying out laser heating, purifying, directly pouring the purified material into a graphite target synthetic unit filled with iron powder and zinc granules, carrying out a synthetic reaction by adopting a laser heating method, and directly monitoring the synthetic conditions through a pressure monitoring display in the synthetic process, thus accurately obtaining a high-quality graphite target needed for dating. Compared with a traditional sample preparation system, the system disclosed by the invention has the advantages that the laser heating method is introduced on the basis that the reliability is improved, so that the heating is centralized and rapid, and the thermal efficiency is high in utilization rate. The graphite target synthesis and a CO2 combustion system are comprehensively integrated, intermediate links are reduced, pollution is avoided, and the dating reliability is improved. The synthetic reaction conditions are monitored by adopting pressure, and the reaction speed is timely known.

Description

technical field [0001] The invention relates to the field of scientific research, in particular to a sample preparation system and method for carbon fourteenth dating of trace organic molecules. Background technique [0002] The global carbon cycle has long controlled atmospheric O 2 and CO 2 and the buried organic carbon in the terrestrial biosphere is one of the key components of the global carbon cycle. However, to date, very little is known about the storage and transport of carbon in these terrestrial biospheres. organic matter at the molecular level 14 The C measurement provides a new window for the exploration and in-depth exploration of the transport dynamics of terrestrial carbon between layers. It has been found that the different organic compounds in sediments 碳十四 The large change in age undoubtedly indicates that the transfer of organic matter in the land-ocean sphere was relatively rapid (years, decadals) or occurred in the range of centuries to millennia. ...

AI Technical Summary

Problems solved by technology

For routine samples, accelerator mass spectrometry 碳十四 The amount of carbon (graphite target) required for dating is about 1 mg, but the content of organic molecules in the sediment is about 5-20 micrograms. Due to the large size of the conventional sample preparation system, there is a greater possibility of vacuum leakage, such as , a conventional system leaks 1 microgram per minute, and the effect on a sample of 1 milligram of carbon is 1‰, but for a sample of 5 micrograms, the effect is 20%

If the conventional sample preparation method is used, it is very easy to be contaminated during the sample preparation process, and a sample preparation system needs to be designed for trace samples

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