MIRAI MR08-05 Primary Production

 Primary Production Data during MR08-05 cruise were obtained by the following methods :
 - In-situ incubation method (IS)
 - Simulated in-situ incubation method (SIS)
 Water sampling, incubation, and devices and tracers for analysis for each method
 are outlined below.
 For further information, please see Cruise Report.
 

 1) In-situ incubation (IS) Outline figure
 1.1)  Vertical sampling : Niskin
 1.2)  Surface sampling :  Bucket
 1.3)  Sampling layer :    8
 1.4)  Tracer :            NaH13CO3, K15NO3
 1.5)  Incubation period : 24hours
 1.6)  Filtration :        Whatman GF/F filter was used at dark place.
 1.7)  Preservation :      Filters were kept to freeze at -20degC and dried
                           in the oven at 45degC.
 1.8)  Preservation period of frozen filter paper : within 30 days
 1.9)  Analysis place :    MIRAI
 1.10) Analysis device :   CN mass spectrometer
 1.11) Analysis method :   Dumas method, Mass spectrometry
 
 2) Simulated in-situ incubation (SIS) Outline figure
 2.1)  Vertical sampling : Niskin
 2.2)  Surface sampling :  Bucket
 2.3)  Sampling layer :    8
 2.4)  Tracer :            NaH13CO3, K15NO3
 2.5)  Incubation period : 24hours
 2.6)  Filtration :        Whatman GF/F filter was used at dark place.
 2.7)  Preservation :      Filters were kept to freeze at -20degC and dried
                           in the oven at 45degC.
 2.8)  Preservation period of frozen filter paper : within 30 days
 2.9)  Analysis place :    MIRAI
 2.10) Analysis device :   CN mass spectrometer
 2.11) Analysis method :   Dumas method, Mass spectrometry
 

 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 CO2, N2, NOx and H2O.
 An elemental copper stage reduces NOx, a MgClO4 trap removes water vapour,
 a switchable Carbosorb trap can be used to remove CO2 (for 15N only analyses)
 and a GC column separates CO2 from N2 (allowing dual isotope analysis).
 And then, it is introduced into the “EUROPA20-20”.
 
 (2) EUROPA20-20
 CO2 and N2 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. MR08-05_pp_ANCA-SL PDF file
 

 (1) ROBOPLEP-SL
 Manufacturer : SerCon Ltd. (former PDZ Europa Ltd.)
 Instruments :  ANCA-SL ROBOPREP-SL
 S/N :          17001-051
 Sample Range Solids/Liquids : 10 to 1000 µgN, 10 to 1000 µgC.
 Autosampler :  60 position pneumatic autosampler that takes (standard) capsules with up to 47mm in diameter.
 
 (2) EUROPA 20-20
 Manufacturer : SerCon Ltd. (former PDZ Europa Ltd.)
 Instruments :  ANCA-SL EUROPA 20-20
 S/N :          9007-075
 Analyzer and Analysis tube : 120° extended geometry with an 11 cm radius magnetic sector
 Resolution :   m/Δm=95 (N2) 10% valley definition
 Sensitivity :  Inside Vacuum level is 4×10-6mbar in an atmosphere of helium
                20 nmol CO2
                15 nmol N2
 Abundance Sensitivity : Inside Vacuum level is 4×10-6mbar in an atmosphere of helium
                30 ppm for CO2 at 4×10-6mbar in continuous flow mode.
                5 ppm for N2 at 4×10-6mbar in continuous flow mode.
 
 (3) Precision
 All specifications are for n=5 samples.
 It is a natural amount and five time standard deviation of the analysis as for amount 100 µg of the sample.
                13C (0.2 ‰)
                15N (0.5 ‰)
 
 (4) Data processing
 Device control and processing soft : ANCA ver.3.5 (former PDZ Europa Ltd.)
 Fully compatible with Windows 3.1 or Windows 95.
 
 (5) Reference material
 The third-order reference materials whose data values were decided by the second reference materials
 (IAEA-N-1, IAEA-N-2, and IAEA-CH-6) dealt in International Atomic Energy Agency (IAEA) were used.