They have masses of 13 and 14 respectively and are referred to as "carbon-13" and "carbon-14." If two atoms have equal numbers of protons but differing numbers of neutrons, one is said to be an "isotope" of the other.Carbon-13 and carbon-14 are thus isotopes of carbon-12.
Signals of this kind are often used by chemists studying natural environments.A hydrocarbon found in beach sediments, for example, might derive from an oil spill or from waxes produced by plants.The pathway from the plant to the molecule may have been indirect or lengthy, involving multiple physical, chemical, and biological processes.Levels of C can represent either mixtures of modern and dead carbon or carbon that was fixed from the atmosphere less than 50,000 years ago.We just believe that it's best to draw a line between sample definition —the investigator's task— and sample processing.
The investigator will always know more about the samples than we do, and s/he should define the sample by removing as much contamination from a sample as possible (e.g., sediment, quartz grains, rootlets) and where there is ample material, by carefully choosing a subsample for AMS analysis. If you are not sure, or expect that less than 100 μg of pure carbon will be extracted in the Sample Prep Lab, please indicate on the NOSAMS Submittal Form whether we may use small sample techniques.Isotopes participate in the same chemical reactions but often at differing rates.When isotopes are to be designated specifically, the chemical symbol is expanded to identify the mass (for example, C is not stable. Along with hydrogen, nitrogen, oxygen, phosphorus, and sulfur, carbon is a building block of biochemical molecules ranging from fats, proteins, and carbohydrates to active substances such as hormones.All carbon atoms have a nucleus containing six protons.When handling samples, wear gloves to avoid imparting any carbon or oils from your skin to the sample. Clear glass or plastic vials and jars are preferred.