CN mass spectrometer system equipped with R/V Mirai can measure stable isotope
ratios of
13C and
15N comprised in liquid, solid, and gas states of
biological or biogenic samples, simultaneously and continuously.
This system consists of two devices, preprocessing equipment “ROBOPLEP-SL” and
stable isotope ratio mass spectrometer “EUROPA20-20”.
(1) ROBOPLEP-SL
A tin capsule containing the sample falls into the combustion tube and is
converted in the presence of oxygen to CO
2, N
2, NO
x and H
2O.
An elemental copper stage reduces NO
x, a MgClO
4 trap removes water vapour,
a switchable Carbosorb trap can be used to remove CO
2 (for
15N only analyses)
and a GC column separates CO
2 from N
2 (allowing dual isotope analysis).
And then, it is introduced into the “EUROPA20-20”.
(2) EUROPA20-20
CO
2 and N
2 are collided with thermion and ionized in the high vacuum ion source.
When the generated ions are accelerated by constant voltage and pass through
the analysis tube, differences in mass (m) and electric charge (z) of isotope
ions make the different orbits by the magnetic field in the analysis tube.
Thus, isotopes can be separated by the displacement of the orbits.
These signals are converted into the frequency at the detector, and transmitted
to control PC. Blank and drift corrections are conducted on the control software.
see flow diagram. MR05-01_pp_ANCA-SL
PDF file