The basic principle behind this method is that each of these radioisotopes spontaneously emits gamma rays at discrete energy levels (46.5Kev, 63.2 & 92.7Kev and 661.7Kev respectively) during their decay which is directly proportional to their concentration.A brief schematic for the radiochemical analysis are shown below.In the BASSIC-03 program sediment cores were collected from box cores and sliced at regular intervals of 0.5 cm (for top 5 cm), 1 cm (for 5-10 cm) and 2 cm (for 10-30cm).
We represent an isotope of carbon-13 as \(\ce\) because carbon has 6 protons and 7 neutrons.
The laboratory is part of the National Isotope Centre based in Wellington.
We have over 30 years of experience, and have established the highest quality of sample preparation, analysis and method development.
Because of the mixing effect the C concentration of the groundwater may differ significantly from those of the fresh precipitate, thus the age of the groundwater cannot be calculated directly from measurement results using the decay law because the initial mixing ratio is not known.
However the average residence time of the groundwater can be estimated from the measured C concentration and stable isotop ratio of the sampled water using the Ingerson&Pearson mixing model.
Search for radiochemical dating:
its input is known; (3) The only change in concentration of the isotope in the sediments is due to radioactive, i.e.