Ⅲ-5

Life, Earth andPlanetary SciencesⅢ -5. Life, Earth and Planetary Sciences
BL4U
BL4U

Different Distribution of DNA and RNA in Chromosome Revealed bySpectromicroscopy with STXM
A. Ito1, K. Shinohara1, H. Yuzawa2 and T. Ohigashi2,3School of Engineering, Tokai University, Hiratsuka 259-1292, JapanUVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
3
SOKENDAI (The Graduate University for Advanced Studies), Okazaki 444-8585, Japan1

2

Spectromicroscopy using scanning transmission Xray microscope (STXM) has been applied to study thedifference in the distributions of DNA and protein in
biological specimens such as chromosome and spermat the C-K absorption edge [1, 2]. In the previous
reports, we developed an image processing procedurefor quantitative mapping of biomolecules, andsuccessfully applied to the distribution of DNA andproteins in mammalian chromosomes using combined
NEXAFS at the C, N and O-K absorption edges [3, 4].
In the present study, we extended our method to thediscrimination of two kinds of nucleic acids, DNA andRNA which have similar chemical composition withslightly different structure: DNA is double-stranded,
while RNA is single-stranded. RNA has a uracil basewith hydrogen at the 5 position, instead of a thymine
base in DNA with a methyl residue at the same
position. In addition, DNA is missing an oxygen at the
2’ position in a ribose sugar.
Figure 1 shows NEXAFS of DNA and RNA at theC, N and O-K absorption edges by the analysis using
aXis 2000 software. Although very similar spectra
were obtained as expected, slightly but significantly
different profile at the C-K edge was observed.
To discriminate the distribution of such closely
related molecules, we introduce the SVD method into
the present method. At first, by using the SVD method,
relative distributions of DNA, RNA and othermolecules including proteins are obtained. The
amount of total nucleic acids was estimated from theheight of the unique peak of nucleic acids in the
NEXAFS at the N-K edge. Quantitative distributionsof DNA and RNA with absolute amount were thencalculated by distributing the total amount of nucleic
acids to each component, DNA and RNA in the imagesof relative amounts.
We used a chromosome for the discrimination of
DNA and RNA. Chromosome was prepared from
cultured Chinese Hamster Ovary (CHO) cells as
described previously [3].
Figure 2 represents RGB maps that demonstrate thedifferent distribution of DNA (red) and RNA (green).
Molecules other than nucleic acids, mainly composedof proteins, are shown by blue.
Interesting observations are as follows:
1) RNA in addition to DNA is also present inchromosomes.
2) RNA distribution was clearly separated from that ofDNA. RNA was preferentially located in the outer areaof a chromosome.

Detailed analysis was reported recently [5]. Theseobservations should be supported by other methods todetect RNA. The proposed procedure is being
successfully applied to RNA distribution in
mammalian cells [6], and in apoptotic nuclei [5].

Fig. 1. NEXAFSof
DNA and RNA.
(a) C-K edge; (b) N-K
edge.; (c) O-K edge.
Red: DNA, Blue: RNA.

Fig. 2. Distribution ofDNA, RNA and othermolecules in a CHO
chromosome.
Red: DNA; Green: RNA;
Other molecules: Blue.
Bar: 0.5 μm[1] H. Ade et al., Science 258 (1992) 972.
[2] X. Zhang et al., J. Struct. Biol. 116 (1996) 335.
[3] A. Ito, K. Shinohara, T. Ohigashi, S. Tone, M.
Kado, Y. Inagaki and N. Kosugi, UVSOR Activity
Report 2017 45 (2018) 156.
[4] K. Shinohara, T. Ohigashi, S. Tone, M. Kado and
A. Ito, Ultramicrosc. 194 (2018) 1.
[5] K. Shinohara, S. Tone, T. Ejima, T. Ohigashi and A.
Ito, Cells 8 (2019) 8.
[6] K. Shinohara, A. Ito, T. Ohigashi, M. Kado and S.
Tone, J. X-Ray Sci. Technol. 26 (2018) 877.

155
Ⅲ05- 1 -Ⅲ- 5

Ⅲ -5. Life, Earth and Planetary Sciences
BL1U
BL1U

Optical Activity Emergence in Amino-Acid Films by Vacuum-Ultraviolet
Circularly-Polarized Light Irradiation (II) - Irradiation Experiments J. Takahashi1, T. Sakamoto1, Y. Izumi2, K. Matsuo2
M. Fujimoto3, M. Katoh3, Y. Kebukawa1 and K. Kobayashi1

Faculty of Engineering, Yokohama National University, Yokohama 250-8501, Japan
2
Hiroshima Synchrotron Radiation Center, Higashi-Hiroshima 739-0046, Japan
3
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan1

Ⅲ- 5

The origin of homochirality in terrestrial bioorganic
compounds (L-amino acid and D-sugar dominant)remains one of the most mysterious problems in the
research for the origins of life. One of the most
attractive hypotheses in the context of astrobiology is“Cosmic Scenario” [1] as below.
(1) Prebiotic simple molecules were densely
accumulated on interstellar dust surfaces in dense
molecular cloud circumstances.
(2) “Chiral radiations” in space induced asymmetric
reactions and produced chiral complex organic
materials including amino-acid precursors as “chiralseeds”.
(3) The “chiral seeds” were transported withmeteorites or asteroids to primitive Earth resulting interrestrial biological homochirality through some kindof “chiral amplification” mechanism.
As for ground experiments to validate the scenario,
we already have reported optical activity emergence insolid-phase films of racemic mixture of alanine (DLalanine) by irradiation of left- or right-handed
circularly polarized light (L- or R-CPL). The CPL
irradiation experiments were carried out in the air at
atmospheric pressure using wavelengths 215 nm fromfree electron laser (FEL) of UVSOR-II [2] and 230,
215, 203 nm from undulator beamline BL1U of
UVSOR-III [3].
We are mainly using circular dichroism (CD)
spectroscopy to detect optical activity emergencebecause CD spectra sensitively reflects the stericstructures of chiral molecules with a high degree of
accuracy. Theoretical calculation of CD spectrum of
alanine molecule has revealed that the circulardichroism chromophores derived from characteristic
electronic transitions (n-π*, π-π* for carboxyl group
and n-σ*, π-σ* for amino group) are corresponding toseveral different wavelengths in 120 ~ 230 nm region[4]. From this point of view, it is suggested that the
expecting aspects of optical activity emergence byasymmetric photochemical reactions strongly depends
on the CPL irradiation wavelength.
We are presently carrying out CPL irradiation
experiments using vacuum-ultraviolet (VUV) light atundulator beamline BL1U of UVSOR-III. In case of
VUV-CPL irradiation of shorter wavelengths than 200
nm, the DL-alanine film samples were set in a vacuum
sample chamber to prevent the attenuation due tophoton absorption band by oxygen molecules in the air[5]. On the undulator beam entrance side of thevacuum sample chamber, a gate valve with a vacuumsealed MgF2 or LiF window was mounted. The
irradiated CPL wavelengths were selected to 180 and
155 nm corresponding to the circular dichroism
chromophores of alanine molecule [4].
CD spectra of the CPL irradiated DL-alanine film
samples were measured at synchrotron radiation CD
beam line BL-12 of Hiroshima Synchrotron Radiation
Center (HiSOR) to clarify the optical activity
emergence by the CPL irradiation. Preferential
structural changes between the two enantiomers inracemic amino-acid mixtures introduced by the CPL
irradiation can be detected by using CD spectroscopy.
In Fig. 1, CD spectra of DL-alanine films after
irradiation with L- and R-CPL at 180 nm (Fig.1(a)) and155 nm (Fig.1(b)) in wavelength are shown. Detailed
analysis of CD spectra are in progress to clarify fullmechanism of the optical activity emergence, which
potentially has relevance to the origin of terrestrial
bioorganic homochirality stimulated by “chiralradiation”.
(a)

(b)

Fig. 1. CD spectra of the L- or R-CPL irradiated DLalanine films measured at BL-12 of HiSOR. The CPL
irradiation wavelengths were (a) 180 nm and (b) 155
nm at BL1U of UVSOR-III.
[1] W. A. Bonner, Orig. Life Evol. Biosph. 21 (1991)
407.
[2] J. Takahashi et al., Int. J. Mol. Sci. 10 (2009) 3044.
[3] K. Matsuo et al., UVSOR Activity Report 2016 44(2017) 157.
[4]F. Kaneko et al., J. Phys. Soc. Jpn. 78 (2009) 013001.
[5] J. Takahashi et al., UVSOR Activity Report 201745 (2018) 147.

156
Ⅲ05- 2 -Ⅲ -5. Life, Earth and Planetary Sciences
BL2B
BL2B

Impacts of Ambient Conditions on the Electronic States ofa Molecular Semiconductor Bis(1,2,5-thiadiazolo)-p-quinobis(1,3-dithiole)
Y. Nakayama1, K. Sudo1 and Y. Watanabe2

Department of Pure and Applied Chemistry, Tokyo University of Science, Noda 278-8510, Japan
Department of Mechanical and Electrical Engineering, Suwa University of Science, Chino 391-0292, Japan1

2

Gaussian03

Intensity / arb. u.

b3-lyp / 6-31g*

PES

hv = 120 eV

BTQBT/Au
10 nm
Au
-12

-10

-8
-6
-4
Binding energy / eV

-20Fig. 1. PES spectra of the Au substrate (orange) and
BTQBT film (red). A simulated DOS curve derived
from the calculated molecular orbital pattern (verticalbars) is also displayed in the upper panel.

(a)

(b)
in air & light(+1 h.)
in air & light(1/12 h.)in air(+12 h.)Normalized intensity

Bis(1,2,5-thiadiazolo)-p-quinobis(1,3-dithiole)(BTQBT) is a promising molecular material for organic
electronics applications because of its widely dispersedintermolecular valence bands in the crystalline thinfilms [1] and good performance in use of vertical field
effect transistor devices [2]. On the other hand, thedegradation under the ambient conditions has been acommon problem for the organic semiconductormaterials. In this study, evolution of the electronic statesof BTQBT thin films grown on Au substrate weretracked before and after exposure to ambient conditions
by means of photoelectron spectroscopy (PES).
BTQBT was deposited on Au-coated Si substrates
in ultra-high vacuum conditions. PES measurements
were conducted at BL2B, UVSOR, by using anelectron spectrometer R3000 (VG-Scienta). The
photon energy was fixed at 120 eV in this work. All
measurements were done at room temperature.
Figure 1 shows PES spectra of the Au substrate and10 nm-thick BTQBT film plotted together with asimulated density-of-states (DOS) curve being
expected from a molecular orbital energy distribution
derived from quantum chemical calculation. Thissuggests that, whereas the spectral profiles of thepresent BTQBT film have to be regarded assuperposition of the DOS of BTQBT and signals fromthe Au substrate, at least the highest-occupied
molecular orbital (HOMO)-derived component of
BTQBT can be separated from the 5d bands of Au.
Evolution of the BTQBT HOMO-derived PES peak
and work function upon exposure to the ambientconditions is shown in Figs. 2(a) and 2(b), respectively.
While the energy positions of the HOMO and vacuum
level were substantially unchanged in ultra-highvacuum (10-7 Pa) condition for more than one month,
an exposure of the BTQBT film to the ambient air in
dark only for 5 minutes brought about a significant (ca.
0.2 eV) decrease and increase in the hole injection
barrier and work function, respectively. Further
exposure induced extra spectral shifts in the same
direction. Interestingly, additional exposure to air withthe ambient light made a change in the opposite
direction, i.e., increase in the hole injection barrier anddecrease in the work function. This implies a
possibility that the presence/absence of the ambient
light may lead to different degradation paths of the
BTQBT-based electronic devices.

in air(+1 h.)
in air
(1/12 h.)in UHV(768 h.)PES
hv = 120 eV
BTQBT (17 nm) / Au

-2

-1

Binding energy / eV

as-prepared
0

3.5
4.0
4.5
Work function / eV

Fig. 2. Evolution of the PES spectra in the (a) HOMO
and (b) secondary electron cutoff regions of the 17 nmthick BTQBT induced by the ambient exposure.
[1] S. Hasegawa et al., J. Chem. Phys. 100 (1994) 6969.
[2] H. Fukagawa et al., AIP Adv. 6 (2016) 045010.

157
Ⅲ05- 3 -Ⅲ- 5

Ⅲ -5. Life, Earth and Planetary Sciences
BL3U
BL3U

X-ray Absorption Spectroscopy Measurement of Lipid Bilayer Membranes
in Aqueous Solutions
1

Ⅲ- 5

R. Tero1, S. Nakamura1, Y. Sano1 and M. Nagasaka2

Toyohashi University of Technology, Toyohashi, 441-8580, Japan
2
Institute for Molecular Science, Okazaki 444-8585, JapanThe lipid bilayer is a self-assembled structure ofamphiphilic lipid molecules, and is the fundamental
structure of biomembranes such as cell membranes.
Lipid bilayer provides reaction fields for transporting
materials, information and energy into and out of cells.
Internal structures of lipid bilayers, e.g. twodimensional domains and hydrophobic thickness, andphysical properties affect the transportation reactions.
All these physiological reactions proceeds in thepresence of ions. Ions in the aqueous solution
significantly influence to these structures andproperties of lipid bilayers. Phosphatidylcholine (PC)
(Fig. 1) is the major component of eukaryotic cells.
Cations bind to the phosphate and carbonyl groups ofPC. However, affinity of cations to PC, and also otherlipids, are still controversy especially in the fields oftheoretical simulations [1]. In this study, we aim todetermine the binding affinity of cations to thephosphate and carbonyl groups experimentally. This
year we started X-ray absorption spectroscopy (XAS)
measurement of a PC bilayer in aqueous solution, todetect the chemical shifts of O 1s binding energy.
We prepared a suspension of dioleoyl-PC (DOPC)
vesicles in a buffer solution using a tip-type sonicator.
We introduced the suspension into the XAS flow cellconsisting of Si3N4 membranes [2]. Planar DOPC
bilayers were formed on the Si3N4 membranes (Fig. 2)
through the process of vesicle fusion method [3].
Fluorescence microscope imaging and fluorescencerecovery after photobleaching method showed that the
Si3N4 membranes were fully covered with planar
DOPC bilayers.
Figure 3 shows an O K-edge spectrum the Si3N4
membrane flow cell with DOPC bilayers on its innersurface. We improved the experimental, and obtained
a peak comprising of several components at 530-533
eV. It was isolated from the peaks of bulk water, whichappeared above 533 eV. The components were
attributed to the phosphate and carbonyl groups of
DOPC, and to the native oxide layer on Si3N4. After
subtracting the blank spectrum of Si3N4 without the
DOPC bilayer, we found that at least two O 1s
components originating from PC, and also that frommolecular oxygen that was dissolved in thehydrophobic core of the bilayer membrane. The DOPC
bilayer existed stably after repeated solution exchange.
We showed that O K-edge spectra of lipid bilayers canbe measured in aqueous solution the XAS flow cell.
Next year we will measure PCs without phosphate or
carbonyl groups, to identify the PC-originated peaks.

Fig. 1. Molecular structure of a representative
phosphatidylcholine.

Fig. 2. Schematic of a lipid bilayer sample in the flow
cell for XAS measurement.

Fig. 3. O K-edge spectrum in absorbance of the Si3N4
membrane covered with a DOPC planar bilayer.
[1] T. B. Woolf, Biophys. J. 104 (2013) 746.
[2] M. Nagasaka, H. Yuzawa, T. Horigome and N.
Kosugi, J. Electron Spectros. Relat. Phenomena 224(2018) 93.
[3] R. Tero, Materials 5 (2012) 2658.

158
Ⅲ05- 4 -Ⅲ -5. Life, Earth and Planetary Sciences
BL3U
BL3U

Study of Micelle Formation in Aqueous Solutions of Fatty Acids Using Soft
X-ray Absorption Spectroscopy
J. J. Lin1, G. Michailoudi1, R. R. Kamal1, H. Yuzawa2, M. Nagasaka3,4 and N. L. Prisle1

Nano and Molecular Systems research unit, University of Oulu, P.O. Box 3000, 90014 University of Oulu, Finland
2
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
3
Institute for Molecular Science, Okazaki 444-8585, Japan
4
School of Physical Sciences, The Graduate University for Advanced Studies (SOKENDAI), Okazaki 444-8585, Japan
1

Atmospheric aerosols have a key role in global
climate as they interact with solar radiation and take partin cloud formation [1]. Fatty acids and their salts arefound both in urban and marine environments, and are
well-known surfactants, meaning that they accumulate
at the liquid/gas interface, including that of water
droplets in the atmosphere. With a hydrophilic head(carboxyl group) and a hydrophobic tail (aliphatic
chain), surface active molecules can form films on thesurface of an aqueous solution, with the heads oriented
towards the water. Above the critical micelleconcentration (CMC), these molecules can selfassemble into structures called micelles, which in turncan impact both chemical and physical properties of thesolutions, including surface tension which play animportant role in cloud microphysics [2, 3].
At BL3U, we studied binary systems of fatty acids inaqueous solutions and also ternary water–fatty acid–salt
solutions with varying concentrations above and below
the respective CMC values, using X-ray absorption
spectroscopy (XAS) on a liquid flow cell [4]. XAS ishighly sensitive to the chemical environment ofdifferent components in solution and provide
information about the bulk properties of dissolved
compounds.
The studied liquid samples were aqueous solutions of
sodium hexanoate (C5H11COONa) at 0.75, 1, 2, 3, 4 and5 CMC (CMC = 0.9 M) and ternary solutions of sodium
hexanoate and sodium chloride salt (H2O–
C5H11COONa–NaCl) at 5.3 M of NaCl andapproximately 1.5 times the ternary CMC for
C7H15COONa. This value is not well-know and basing
the concentration on a multiple of CMC involves
estimating the dependency of CMC on solution saltcontent. Spectra of pure hexanoic acid (C5H11COOH)
and aqueous C5H11COOH solution (7.3 M) were alsomeasured as a reference.
The thickness of the liquid cell was optimized forbetter absorption and the sample temperature was set at25C. We monitored solution properties of surfactant
molecules and their micelle formation by scanning theC K-edge from 280 to 300 eV, in energy steps of 0.02
eV from 285 to 290 eV and 0.1 eV for the remainder ofthe range.
Figure 1 presents a preliminary analysis at the C Kedge XAS spectra for binary and ternary solutions, after
normalization at the peak position. A background

spectrum of absorption from water was subtracted,
removing also signal from carbon contamination on theliquid cell membranes. Solutions with highest
concentration resemble the pure acid. Furthermore, theratio of the pre-peak feature to main peak changes withthe concentration of the surfactant relative to the CMC.
From such changes and energy shifts on peak positionof our spectra, we expect to extract information about
the structures present in each solution.
Further analysis is needed to fully interpret the
spectra, including an appropriate fitting procedure andidentifying underlying peaks from the occurring
excitations in the C K-edge from comparison totheoretical predictions. Model predictions for these andsimilar systems are the focus of ongoing work.

Ⅲ- 5

Fig. 1. C K-edge XAS spectra of pure C5H11COOH,
aqueous C5H11COOH and aqueous C5H11COONa
solutions at various multiples of the CMC value, andof H2O–C7H15COONa–NaCl ternary solution.
[1] Intergovernmental Panel on Climate Change:
Climate Change 2013: The Physical Science Basis,
Cambridge University Press, New York, USA, 2013.
[2] P.S. Gill et al., Rev. Geophys. 21 (1983) 903.
[3] M.C. Facchini et al., Atmos. Environ. 34 (2000)
4853.
[4] M. Nagasaka et al., J. Electron Spectrosc. Relat.
Phenom. 224 (2018) 93.

159
Ⅲ05- 5 -Ⅲ -5. Life, Earth and Planetary Sciences
BL4U
BL4U

Estimation of the Thickness of Fe(III)-oxides Layer near the Magnetite (111)
Surface after Hydrothermal Treatment
T. Tamura, A. Kyono and I. Kinebuchi

Division of Earth Evolution Sciences, Graduate School of Life and Environmental Sciences, University ofTsukuba, Tsukuba 305-8572, JapanⅢ- 5

Since the discovery of hydrothermal chimneys andblack smoker vents in 1979 [1], a great variety ofhydrothermal vents has been found all over the world[2-4]. Some of them are characterized by hydrothermal
fluids enriched in molecular hydrogen (H2) [5].
Previous studies have shown that the hydrogengeneration can be induced by water-magnetiteinteraction [6, 7]. Furthermore, it has been reported thatthe reaction is accompanied by oxidation of magnetite(Fe3O4) to maghemite (γ–Fe2O3) [7], but themechanism has been still unknown. In the study, we
employed a scanning transmission X-ray microscopy(STXM) to estimate the thickness of maghemite layer.
About 0.02 g of synthesized magnetite crystals wereintroduced into the 28 ml Teflon–lined stainless steel
autoclave. Ultrapure water was in advance sufficiently
bubbled with N2 gas to remove dissolved O2. 14 ml of
the deoxidized water were added into the Teflon
container. The autoclave was tightly sealed and thenheated at 200 °C for 24 hours. After the hydrothermal
treatment, the magnetite crystals were removed fromthe Teflon container and dried at room temperature.
After amorphous carbon was deposited on the sample
surface, a cross–section was prepared with a JEOL
JEM–9320FIB focused ion beam (FIB) system using a
30 keV Ga ion source. The FIB cross–section was
analyzed using a STXM at UVSOR branch line 4U.
The Fe L23 edges provide chemical information
about valence-specific multiplet structures of ironwhich can be used as valence fingerprints. In the study,
the Fe L3 and L2 edges were clearly observed at around709 and 722 eV, respectively (Fig. 1). The L3 edge
shape obtained at a depth of 100 nm seemed to be split,
which suggesting that hematite is formed at the surface.
With increasing the depth, the split peaks of L3 edge
were merged into one broad peak. The Fe L2 edge
peaks at 721.0 and 722.5 eV were, on the other hand,continuously observed up to a depth of 800 nm, but anew peak at 721.5 eV became dominant from 900 nm(Fig. 1). The result implies that maghemite (γ-Fe2O3)
is dominantly distributed between 100 nm and 800 nm.
Therefore, we can conclude that during hydrothermal
reaction magnetite is oxidized to hematite throughmaghemite.

Fig. 1 (a) Fe distribution map of cross-section
perpendicular to hydrothermally treated (111)magnetite surface. The box size is 100 nm of depth. (b)Fe L23 edge XANES spectra of hydrothermally treatedmagnetite resulting from the image stack on the area
depicted in (a). Reference spectra of as grownmagnetite is also shown for comparison.
[1] Corliss et al., Science 203 (1979) 1073.
[2] Hekinian et al., Science 219 (1983) 1321.
[3] Azuende et al., J. Geophys. Res. 101 (1996) 17995.
[4] Connelly et al., Nat. Commun. 620 (2012) 1.
[5] Kelley et al., Science 307 (2005) 1428.
[6] Mayhew et al., Nat Geosci. 6 (2013) 478.
[7] Tamura et al., J. Mineral. Petrol. Sci. 113 (2018)310.
[8] Almeida et al., Nat. Commun. 5154 (2014) 1.

160
Ⅲ05- 6 -Ⅲ -5. Life, Earth and Planetary Sciences
BL4U
BL4U

Investigating the Effect of Space Exposure Experiment on Carbonaceous
Dust Based on XANES/STXM Analysis
I. Sakon1, I. Endo1, H. Yabuta2 and T. Noguchi3

Department of Astronomy, Graduate School of Science, University of Tokyo, Tokyo 113-0033, Japan
2
Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan
3
Division for Experimental Natural Science, Faculty of Arts and Science, Kyushu University, Fukuoka 819-0395, Japan1

We have carried out the space exposure experimentof various kinds of carbonaceous solids using
International Space Station (ISS) Japanese Experiment
Module ‘Kibo’ ExHAM (See the top panel of Fig. 1).
The major goal of this project is to understand how the
carbonaceous dust particles synthesized in the stellar
ejecta from evolved stars are chemically and physicallyaltered in nature in the circumstellar environment until
it becomes a member of the interstellar medium. In
particular, we aim to investigate the propertiesof ’astronomical’ polycyclic aromatic hydrocarbons(PAHs), the carrier of the unidentified infrared (UIR)bands, which have been observed ubiquitously invarious astrophysical environments [1]. So far, we havebrought three experiment samples to the ISS. Eachexperiment sample has a 10cm x 10cm exposure surface
and has 64 slots for exposure experiment materials. In
total, more than 40 kinds of materials including filmy
quenched carbonaceous composites (filmy-QCCs [2]),nitrogen-included carbonaceous composites (NCCs [3]),anthracite, graphite, and silicates are installed in theexperiment samples. Among the three samples, two ofthem (EE64-I and EE64-II) were attached on ExHAM1 and were exposed in the space exposure environmentfor 384 days from 26 May 2015 to 13 June 2016. The
final sample (EE64-III) was attached on ExHAM-1 andwas exposed for 386 days from 29 June 2016 to 19 July
2017. All the samples are now collected back on earth
and the difference in properties of our exposure
experiment materials between before and after theexperiment is investigated based on infrared microspectroscopy.
The bottom panel of Fig. 1 shows the comparison of
the infrared spectra of the filmy-QCC before and after
the experiment. In addition to the presence of newfeatures at 2.95 µm, attributed to O-H stretching withmoderate hydrogen-bonding, and at 5.95 µm, attributed
to C=O stretching of conjugated ketone and/or aldehyde,
a broad bump structure in 8-10 µm has been recognized.
In order to identify the effect of space exposure on thefilmy-QCC, we have carried out the XANES/STXM
analyses of TEM samples made by FIB processing offilmy-QCC (U-02 in EE64-I) and non-exposed filmyQCC as a reference.
Our beamtime using the BL4U STXM beamline of
the UVSOR was scheduled on July 24-25 in 2018,
however, we still have not yet obtained the conclusive
results of the XANES/STXM measurement due to beam
trouble that has happened in July 2018. We haveproposed an another try in this semester (first half of2019) and the beamtime was allocated in this June and
July.

Ⅲ- 5

Fig. 1. [Top] A photo of space exposure experimentof EE64-I and EE64-II attached to ExHAM (credit:
JAXA/NAXA), [Bottom] The comparison of theinfrared spectra of the filmy-QCC before and after the
space exposure experiment.
[1] A. T. Tokunaga, ASP Conf. Ser. 124 (1997) 149.
[2] A. Sakata et al., Nature 301 (1983) 493.
[3] I. Sakon et al., Asian Journal of Physics 24 (2015)
1143.

161
Ⅲ05- 7 -Ⅲ -5. Life, Earth and Planetary Sciences
BL4U
BL4U

Investigation of Origin and Evolution of Organic Material inside theExtraterrestrial Material with a Series of in-situ Analyses: Construction of
System for the Inter-facility Collaboration for the Analysis of Hayabusa2
Returned Samples
M. Uesugi1, M. Ito2, K. Tomioka2, Y. Kodama3, T. Ohigashi 4,5, H. Yuzawa4, K. Uesugi1,
A. Yamaguchi6, N. Imae6, Y. Karouji7, N. Shirai8, T. Yada9 and M. Abe91
Japan synchrotron radiation research institute (JASRI/SPring-8), Sayo 679-5198, Japan
Kochi Institute for Core Sample Research, Japan Agency for Marine-Earth Science Technology (JAMSTEC),
Nankoku 783-8502, Japan
3
Marine Works Japan Ltd., Yokosuka 237-0063, Japan
4
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
5
School of Physical Sciences, The Graduate University for Advanced Studies (SOKENDAI), Okazaki 444-8585, Japan
6
Antarctic Meteorite Research Center, National Institute of Polar Research, Tachikawa 190-8518, Japan
7
Space Exploration Innovation Hub Center, Japan Aerospace Exploration Agency (JAXA), Sagamihara 252-5210,
Japan
8
Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Hachioji 192-0397, Japan
9
Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA), Sagamihara 252-5210,
Japan
2

Ⅲ- 5

Hayabusa2 spacecraft successfully touched downon the surface of asteroid Ryugu, in Feb. 2019. It isscheduled that the spacecraft will return back to the
Earth in 2020, with the sample of Ryugu [1].
Reflectance spectrum of the surface of Ryugu
suggested that the sample would have water andcarbonaceous materials, those similar to carbonaceouschondrites found on the Earth.
We started the development of techniques anddevices for the handling, transfer and analysis ofsamples returned by Hayabusa2 spacecraft from 2015,
by organizing a special team constituting of membersof Japan Aerospace Exploration Agency (JAXA),
Japan Agency for Marine-Earth Science andTechnology (JAMSTEC), Institute for Molecular
Sciences (IMS), SPring-8 and National Institute ofPolar Research (NIPR) [2]. The team, called Phase 2
team Kochi, will also analyze the Hayabusa2 returned
samples from 2021.
Rehearsal of the analysis of Hayabusa2 returned
samples was started in 2017 using Antarctic micrometeorites (AMMs) which simulated the small returned
particles. 10 AMMs, with diameter around 100µm,
provided by NIPR were observed by synchrotron
radiation computed tomography (SR-CT) and x-ray
diffraction (XRD) at SPring-8, high resolution fieldemission scanning electron microscopy and energy
dispersive spectroscopy (FE-SEM-EDS) system at IMS.
Through the series of non-destructive analysis, weselected two AMMs those having characteristics similar
to carbonaceous chondrites, and extracted thin sections
by focused ion beam (FIB) for the analysis of organic
materials by scanning transmitted x-ray microscopy andx-ray absorption near edge structure (STXM-XANES)
at BL4U.

We found two different phases of organic matter in
AMMs, spotty particles with high carbon density andbroad distribution of organics with low density ofcarbon, in C-XANES analysis. They also show different
C-XANES spectrum, suggesting different origin or
evolutional history. Though spatial resolution is notenough to resolve precise structure of those phases, highresolution analysis by transmission electron microscopy(TEM) at JAMSTEC revealed that the spotty particles
are hollow organic globules (HOG) those are previously
reported by literatures [3][4]. However, the number
density of the HOG is almost ten times higher thanprevious result obtained by TEM [3]. This means thatwide-area observation of organics by STXM-XANES,
with spatial resolution less around 0.1 µm, is important
for analysis of extraterrestrial organic material, and alsocharacterization of parent extraterrestrial material.
In future works, we will examine otherextraterrestrial materials, such as hydrated and/or
heated carbonaceous chondrites with same manner.
[1] S. Tachibana et al., Geochemical Journal 48 (2014)571.
[2] M. Ito et al., LPSC conf. (2019) abstract#1394.
[3] K. Nakamura-Messenger et al., Int. J. Astrobiol. 1(2002) 179.
[4] L.A. Garvie, P. R. Buseck Earth. Planet. Sci. Lett.
224 (2004) 431.

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Aqueous Alteration Scenario in Martian Meteorite Based on Chemical
Speciation
N. Shiraishi1, H. Suga1, M. Miyahara1, T. Ohigashi2, Y. Inagaki2, A. Yamaguchi3,
N. Tomioka4, Y. Kodama5 and E. Ohtani6

Department of Earth and Planetary Systems Science, Graduate School of Science, Hiroshima University,
Higashi-Hiroshima 739-8526, Japan
2
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
3
National Institute of Polar Research, Tokyo 190-8518, Japan
4
Kochi Institute for Core Sample Research, Japan Agency for Marine-Earth Science and Technology, Nankoku
783-8502, Japan
5
Marine Works Japan, Nankoku 783-8502, Japan
6
Department of Earth Sciences, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan.
1

Previous studies showed that Martian meteorite clan
nakhlite has evidence for a rock-fluid reaction occurredon the Mars. One of the representative fingerprints forthe rock-fluid reaction is “iddingsite”, which is thealteration texture formed in and around the olivine
grains of nakhlites. Iddingsite is the assemblages of any
kinds of secondary minerals. The mineral species,
compositions, and chemical species of the iddingsite
depend on the varied parameters such as temperatureand pH of the fluid contributing to the reaction [e.g., 1].
Accordingly, the secondary minerals in the iddingsite
allow us to elucidate the physicochemical properties ofthe fluid in ancient Martian subsurface and its origin.
In this study, we clarified the mineral species,
chemical compositions, and chemical species of thesecondary minerals in the iddingsite of the nakhlite
Yamato 000749 (Y 000749) using a combined SEMRaman-FIB-TEM-STXM technique. In particular, FIBSTXM measurement is a unique point of this study. We
performed two-dimensional chemical state analysis
using X-ray absorption near edge structure (XANES).
TEM images revealed that the iddingsite in Y 000749
had a layer structure (oxidized olivine: laihunite–
ferrihydrite–low crystalline silica minerals in Fig. 1a).
Fe-XANES spectra revealed that most irons in theoriginal olivine and iddingsite were divalent andtrivalent, respectively (Fig. 1b). Based on O-XANES
spectra (Fig. 1c) and TEM observations, most of theiron oxides in the iddingsite of Y000749 were identified
as ferrihydrite. In addition, S-XANES spectra and TEM
observations revealed that a small amount of iron sulfate
mineral coexisted with ferrihydrite.
On the basis of the occurrences and formation
conditions of the secondary minerals, we expect that Y
000749 experienced three different alteration events atleast. The alteration of Y000749 was initiated by theformation of ferrihydrite subsequent to the formation oflaihunite, which occurred under high-temperature andhigh-pH conditions [2]. Then, silicon dissolved in thefluid precipitated as low-crystalline silica minerals. Thus,by combining the FIB-STXM analysis of secondary
minerals with the conventional model calculations, we
can disclose more detailed environmental evolution
processes on Mars.

Ⅲ- 5

Fig. 1. a) HAADF-STEM image, b) Fe-XANES,c) O-XANES of the iddingsite in Y 000749.
[1] Bridges J.C. and Grady M.M., Earth Planet. Sci.
Lett. 176 (2000) 267.
[2] Treiman A.H., Chem Erde-Geochem 65 (2005)
203.

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Sulfur Map in Organics in Meteorites by STXM-XANES and NanoSIMS
M. Ito1, R. Nakada1, H. Suga2, T. Ohigashi3, Y. Kodama4 and H. Naraoka5

Kochi Inst. for Core Sample Res., JAMSTEC, Nankoku 783-0086, Japan
2
The University of Tokyo, Tokyo 113-8654, Japan
3
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
4
Marine Works Japan, Yokosuka, 237-0063, Japan
5
The Kyushu University, Fukuoka, 812-0053, Japan1

Ⅲ- 5

and peak-top shape. We found several µm-sized spots
having the S-STXM spectra in the Tagish Lake section.
We, then, conducted S (red), C (green), and O (blue)
elemental imaging with the JAMSTEC NanoSIMS for
the Murchison FIB section in comparison with the
STXM image (red: Sulfate, green: IOM, blue: DiffOM)of the same FIB section (Fig. 2). Note that the green
area in both images are almost identical each other
implying NanoSIMS C-image are relate to the IOM.
However, S regions from both sections showcompletely different locations within the entire section.
S distributions observed by STXM is an organic
component, but S image obtained by NanoSIMS might
be inorganic components (i.e., FeS).
Sulfonate: 181eV

R:S (173.6eV), G: IOM, B:DiffOM

Sulfate: 173.6eV

Sulfide:164eVa) Murchison
AbsorbanceOrganic matter in carbonaceous chondrites iscomposed of an insoluble macromolecule (akainsoluble organic matter: IOM) and complex solubleorganic molecules (OM). The total organic content isaround 4 wt% in chondrites (IOM of ~75 wt%) [1].
The proposed composition of IOM is C100H70O22N3S7[1] or C100H48N1.8O12S2 [2].
The STXM studies were carried out to identifyfunctional groups of C, N and O in organics ofextraterrestrial materials (IOM in chondrites [3],cometary returned sample [4], organics in Hayabusa
Category-3 particles [5], organics in IDPs [6], andorganics extracted from halite in the Monahans LL
chondrite [7]). However, sulfur study by XANES in theextraterrestrial organics is very rare [8, 9].
In our experiments at Inst. Mole Sci. UVSOR
synchrotron BL4U, we have reported nine sulfur L3edge spectra from sulfur bearing terrestrial organics;
sodium lauryl sulfate, sodium methanesulfonate,
dibenzothiophene, thianthrene, DL-methionie, DLmethionine sulfone, L-cysteic acid, L-cystein, and Lcystine showing different absorption curves (e.g.,sulfate, sulfone, thiol) [10].
In this study, we report preliminary results of sulfur
speciation measurements by S-XANES in the FIB
sections of the Murchison and the Tagish Lake meteorites
using scanning transmission X-ray microscope (STXM)
at the BL4U. The purpose of this study is understandingof sulfur speciation, its distribution and isotopic
compositions (33S/32S, 34S/32S, 36S/32S) within organics ina carbonaceous chondrite which may provide thesecondary alteration processes of thermal metamorphism
and aqueous alteration in the parent body.
We successfully obtained high resolution S-STXM
image of FIB sections from the Murchison (147 x 187
pixels, 22 x 28 µm2: spatial resolution = 150 nm) andthe Tagish Lake meteorites (01L section = 132 x 132
pixels, 33 x 33 µm2 and spatial resolution = 250 nm).
Figure 1a shows S-STXM (Red: 173.6 eV assigned tosulfate) image together with IOM (Green) and diffused
OM (Blue) images in the Murchison FIB section.
Figure 1b is a representative S-XANES spectra in the
Murchison FIB section. First and second strong peaks
in Fig. 1b may be related to sulfate based on ourprevious sulfur L3-edge spectra for organic standards[10]. We might find small peak around 181 eV whichassigned to sulfonate in Fig. 1b, and difficult to assign
164 eV peak which is related to organic sulfide. The SSTXM spectra of Tagish Lake is slightly different peaks

Energy / eV

Figure 1. a) STXM image of Murchison FIB section, and b) S-XANES
spectra of the Murchison and Tagish Lake meteorites

R:32S, G: 12C2, B:16Oa) NanoSIMS

R:S (Sulfate : 173.6eV), G: IOM, B:DiffOMb) STXM

Figure 2. Comparison a) NanoSIMS elemental image and b) STXM image[1] Remusat, EPJ Web of Conferences 18 (2011) 05002.
[2] Gilmour, In Meteorit., comets and planets, Treatiseon Geochemistry, (2005) 269.
[3] Kebukawa et al. 2019. Scientific Reports, 9:3169.
[4] Sanford et al., Science 314 (2006) 1720.
[5] Yabuta et al.,. EPS 66 (2014) 156.
[6] Flynn et al., Geochim Cosmochim Acta 67 (2003)
4791.
[7] Chan et al,. Science Advance 4 (2018) eaao3521.
[8] Orthous-Daunay et al., EPSL 300 (2010) 321.
[9] Bose et al., Meteor Planet Sci. 52 (2017) 546.
[10] Ito et al., UVSOR activity report 2017 45 (2018) 84.

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Hyperspectral Imaging by Scanning X-ray Microscopy:
Probing the Penetration of Rapamycin in Fixed Human Skin
G. Germer1, T. Ohigashi2, H. Yuzawa2, F. Rancan3, A. Vogt3 and E. Rühl1

Physical Chemistry, Freie Universität Berlin, Arnimallee 22, 14195 Berlin, Germany
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
3
Charité Universitätsmedizin, 10117 Berlin, Germany
1

2

Progress in hyperspectral imaging using scanning Xray microscopy is reported. This is facilitated by using acustom-made Ni-coated zone plate for investigations in
the O 1s-regime, which provides higher photon flux andimproved spatial resolution compared to previous beamtimes. This substantial improvement allowed us to takefor fixed human skin sample stacks of images, which
cover multiple photon energies in the O 1s regime (520
– 560 eV, 134 energy steps) in areas of a size of 20 μm
x 5 μm with 100 nm step width as well as high resolution
maps with 30 nm step width (size: 4 μm x 2 μm). This
provides substantially more detailed information than in
our previous work, where X-ray micrographs weretaken at a few pre-selected photon energies [1]. These
were chosen according to characteristic changes inabsorption of the species under study, allowing for
determining the location of the penetrating drug. The
present developments go beyond, so that the spectral
shapes in the near-edge regime as well as theirdifferences can also be used for identifying highly dilute
species in a given compartment of biological matter.
This is of importance for identifying local changes
induced by topical drug delivery. We have investigated
for the first time the skin penetration of the antiinflammatory drug rapamycin (sirolimus) (C51H79NO13,
M=914.13 g/mol), a well-known mTOR inhibitor. Skin
penetration of rapamycin is expected to be inefficientdue to its high molecular mass [2], if not properly
formulated. The present studies were performed at theO 1s-edge, where the drug is selectively probed at the O
1s→π*-resonance near 531 eV, which ischaracteristically shifted in energy compared to thematrix of fixed human skin. The skin was partiallytreated before drug penetration by serine protease [3],enhancing the drug penetration. This was verified for
rapamycin dissolved in ethanol, where the drug was
only observed in the stratum corneum in the lipophilic
membranes between the corneocytes after long
penetration times, reaching up to 1000 min (see Fig. 1).
In contrast, intact skin samples do not provide evidence
for such drug penetration, underscoring the successful
use of primary serine protease treatment as aprerequisite for drug penetration. Figure 1(a) shows ahigh resolution micrograph of such skin sample. Clearlyvisible is the stratified structure of the stratum corneum(SC). Distinct changes in local composition are visibleat the locations A and B. The raw spectra (Fig. 1(b))
show only minor differences in shape, but when thecontribution of a reference skin sample is subtracted(see Fig. (1c)), then evidence is found for the local
abundance of rapamycin (location A), whereas incorneocytes (location B) only enhanced intensity in the
O 1s continuum is observed (see Fig. 1(c)). This
progress will be systematically exploited for subsequentstudies involving redox nanocarriers for bringing the
drug efficiently in viable skin layers.

Ⅲ- 5

Fig. 1. (a) X-ray micrograph of fixed human skintreated with serine protease and subsequently exposedfor 1000 min with rapamycin (R), SC: stratum
corneum, A: lipophic lamella; B: corneoyte; (b) X-ray
absorption spectra at the locations A and B at the O 1sedge; (c) reference spectrum of rapamycin and at thelocations A and B subtracted by the contribution ofreference skin (A-Ref; B-Ref). The insets in (b) and (c)show the O 1s→π*-bands in greater detail.
[1] K. Yamamoto et al., Anal. Chem. 87 (2015) 6173;
Eur. J. Pharm. Biopharm. 118 (2017) 30; Eur. J. Pharm.
Biopharm. 139 (2019) 68.
[2] J. D. Bos et al., Exp. Dermatol. 9 (2000) 165.
[3] J. Frombach et al., Z. Phys. Chem. 232 (2018) 919.

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Ultrastructural Features in Mice Liver Samples Imaged Using STXM
M. Patanen1,2, H. Yuzawa3, T. Ohigashi3, T. Mansikkala1,2, I. Miinalainen2, S. M. Kangas2,4,
A. E. Hiltunen2,4, E.-V. Immonen1,4, R. Hinttala 2,4, J. Uusimaa2,4, N. Kosugi3 and M. Huttula1
Nano and Molecular Systems Research Unit, PO Box 3000, 90014 University of Oulu, Finland
2
Biocenter Oulu, PO Box 5000, 90014 University of Oulu, Finland
3
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
4
PEDEGO Research Unit and Medical Research Center Oulu, and Oulu University Hospital, PO Box 5000,
90014 University of Oulu, Finland1

Ⅲ- 5

In this work, we have used scanning transmission Xray microscopy (STXM) technique at BL4U beamline
to study liver tissue samples of control (healthy) miceand mice with a mutation in NHLRC2 gene. The
NHLRC2 gene encodes an NHL repeat containing
protein 2 ubiquitously present in various types of tissues,
from animals to bacteria. Recently, we havecharacterized a novel, fatal cerebropulmonary disease inchildren with fibrosis, neurodegeneration and cerebral
angiomatosis (FINCA disease) [1]. FINCA disease has
been linked to mutations in NHLRC2, but the functionalrole of the NHLRC2 is still unknown. Transmission
Electron Microscopy (TEM) images of analysis ofimmortalized cell cultures from FINCA patientsdemonstrated multi lamellar bodies and distinctly
organized vimentin filaments, and based on thoroughmultitechnique characterization, it was suggested that
NHLRC2 dysfunction enhances tissue fibrosis [2].
Previously, we have also reported an STXM study ofhuman FINCA patient tissue samples which were in linewith TEM results [3].
Recently, we have created a knock-in mouse model for
FINCA disease utilizing the CRISPR-Cas9 technology.
This mouse model enables us to investigate the changes
in ultrastructural features as the disease progresses. For
the present study, liver sections from control mice andknock-in mice were collected from 13 weeks old mice.
Tissue samples were fixed in 4% paraformaldehyde and2.5% glutaraldehyde in 0.1 M phosphate-buffered saline.
Prior to embedding in resin some samples were stainedwith 1% OsO4 and/or uranyl acetate. Some samples wereleft without staining in order to investigate its effects. The
100 nm thick sections of resin-embedded sample were
measured first with STXM, and then further imaged at
Biocenter Oulu using a Tecnai G2 Spirit 120kV TEM(FEI, Eindhoven, The Netherlands) equipped with aQuemesa CCD camera (Olympus Soft Imaging Solutions
GmbH, Münster, Germany).
Figure 1 shows examples of a FINCA mouse liver
section without block staining imaged with STXM andafter with TEM. Radiation damage seems to thin thesample, as the STXM imaged regions are clearly visible
as lighter regions in TEM images. However, noultrastructural changes in sample due to radiation wereobserved. The average STXM image taken over the O
K-edge is presented in optical density, in contrast totransmission mode of TEM images. A cluster analysis
of STXM image stacks (Figs. 1c & f) was performed

using a MANTiS software [4]. Even with the resinembedded unstained samples, the cluster analysis wasable to differentiate cell components rather consistently
based on their spectral information. For example, theFigs. 1b-d contain a cell nucleus with a nucleolus, which
the cluster analysis also catches, and in Fig. 1f
mitochondria (orange) are well separated from thesurrounding endoplasmic reticulum (green). The resultshows great promise in ultrastructural characterizationof unstained tissue samples using STXM.

Fig. 1. (a) TEM image of the FINCA mouse sample
studied after STXM. (b) & (e) Higher resolution TEM
images of the studied areas. (c) & (f) Cluster analysisof the STXM image stacks. (d) & (g) Average STXM
image recorded over O K-edge.
[1] J. Uusimaa et al., Acta Neuropathol. 135 (2018) 727.
[2] T. Paakkola et al., Hum. Mol. Gen. 27 (2018) 4288.
[3] E.-V. Immonen et al., UVSOR Activity Report 201745 (2018) 161.
[4] M. Lerotic et al., J. Synchr. Rad. 21 (2014) 1206.

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The Molecular Structures and Distributions of Organic Matter Depending on
the Lithologies of the Tagish Lake Meteorite Examined by C- and Fe-XANES
1

K. Kiryu1, Y. Kebukawa2, T. Ohigashi3 and K. Kobayashi2

Graduate School of Engineering Science, Yokohama National University, Yokohama 240-8501, Japan
2
Faculty of Engineering, Yokohama National University, Yokohama 240-8501, Japan
3
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, JapanThe Tagish Lake meteorite is an anomalous
carbonaceous chondrite (CC) and contains abundantorganic matter (OM) which has been affected byaqueous alteration in the parent bodies [1]. In theprocess of aqueous alteration, specific minerals may be
involved in the reaction of OM. In fact, the distributionsof OM overlap with these of phyllosilicates and partiallycarbonates in Tagish Lake [2]. Phyllosilicates are
known to adsorb OM [e.g., 3], and thus they possibly
serve as catalysts of the reactions of OM [e.g., 4, 5].
Tagish Lake is known to consist of various lithologies[1, 6]. Therefore, we aim to evaluate the relationships
between minerals and OM through microscopic
analyses of various lithologies of the Tagish Lake
meteorite.
Fragments from three different lithologies of Tagish
Lake (“Pristine”, “KN2”, and “Degraded” samples)
were observed using a scanning electron microscope(SEM) and energy dispersive X-ray spectroscopy(EDS). We selected four areas randomly and two areas
based on the EDS (a Mg-rich region and a carbonate
region). Six ultrathin sections (~100 nm thick) wereprepared using focused ion beam (FIB). We analyzed
these sections by scanning transmission X-ray
microscope (STXM) and obtained C- and Fe-X-ray
absorption near-edge structure (XANES) from C-richregions in the FIB sections. The C-XANES spectra of
Tagish Lake showed peaks at 287.3 eV (aliphatic C),
285.2 eV (aromatic C), 288.5 eV (carboxyl and/or
ester) and 290.3 eV (carbonate) (Fig. 1), and the FeXANES spectra showed peaks at 706.8 eV (Fe2+) and
708.5 eV (Fe3+) (Fig. 2).
To compare molecular structures of OM in various
fragments from Tagish Lake, C-XANES peakintensities were normalized to the intensity at 291.5 eV(ionization potential). The normalized intensities ofaliphatic C were KN2 (carbonate region) > Pristine ≥KN2 (Mg-rich region) > KN2 > Degraded. The
Fe2+/Fe3+ ratios were lower in the OM rich regions
compared to the OM poor regions. These results
indicate that the molecular structure of OM varies
among lithologies of Tagish Lake, possibly related tochemical compositions of coexisting minerals.
Acknowledgements: We thank Dr. M. E. Zolensky and
Dr. W. Fujiya for providing the Tagish Lake meteorite
samples, and Dr. M. Ito for preparing the FIB sections.

Fig. 1. C-XANES obtained from a FIB section of
Tagish Lake “KN2”.

Ⅲ- 5

Fig. 2. Fe-XANES obtained from a FIB section of
Tagish Lake “KN2” (same region to Fig. 1).
[1] C. D. K. Herd et al., Science 332 (2011) 1304.
[2] M. Yesiltas and Y. Kebukawa, Meteoritics &Planetary Science 51 (2016) 584.
[3] M. Kahle et al., Organic Geochemistry 35 (2004)
269.
[4] L. B. Williams et al, Geology 33 (2005) 913.
[5] J. S. Watson and M. A. Sephton, Astrobiology 15(2015) 787.
[6] M. E. Zolensky et al., Meteoritics & Planetary
Science 37 (2002) 737.

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BL4U

Composition of Carbon Functional Group of Soil Organic Matter in Clay
Size Fraction in Initial Forming Stage of Volcanic Ash Soils in Japan
M. Asano 1, V. F. Eseese 2, H. Shimada 2, K. Tamura 1 and T. Ohigashi 3,4

Fuculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba 305-8572, Japan
Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba 305-8572, Japan
3
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
4
School of Physical Sciences, The Graduate University for Advanced Studies (SOKENDAI), Okazaki 444-8585, Japan
1

2

Ⅲ- 5

Soil is the largest terrestrial carbon reservoir in theWorld. Soil organic matter (SOM) accounts for amajor portion of terrestrial C and is considered to bestabilized against microbial degradation due partly to
its interaction with soil minerals. These organomineral interactions contribute to the formation ofheterogeneous organo-mineral particles at various
space scales down to submicron level [1]. Volcanic ash
soil tend to accumulate large amounts of carbon as
SOM in comparison to other soil type. The abundanceof Short Range Order minerals and secondary Al, Fe
and Si–humus complexes are common in developed
volcanic ash soil (Andosols) which contributes to its
SOM accumulation capacity [2]. On the other hand,the changing of organo-mineral interactions withweathering process on fresh volcanic ash during soil
forming is remain unclear. The research on initial soil
forming process on fresh volcanic ash under naturalenvironment is important to understand thedevelopment of Andosols and carbon dynamics involcanic region.
Here we focused on the carbon functional groups
within the organo-mineral particle in the initial soil
forming stages using scanning transmission X-ray
microscopy (STXM) and near-edge X-ray absorption
fine structure (NEXAFS) at UVSOR BL4U. We
compared top soil from different soil ages, immature
volcanic ash soil (Regosol) and mature volcanic ash
soil (Andosol). The smaller than 2 µm fraction was
separated by particle size fractionation method [3].
The C-NEXAFS spectrum of organo-mineralparticles showed clear difference between Regosol andAndosol. To show the C chemical composition map,
we split the C K-edge spectra three energy regions,
284–286 eV (aromatic C), 286–287 eV (phenol andaliphatic C), and 287–289 eV (amid and carboxyl C)(Figs. 1 and 2). The C functional group map ofRegosol was dominated by carboxylic C with minimal
Aliphatic C and Aromatic C (Fig. 1). The C functionalgroup map of Andosol shows also dominated bycarboxyl C, but Aromatic C and Aliphatic C appeared
clear than Regosol (Fig. 2). Those results indicatedamide and carboxylic C, potentially labile C, wasaccumulated in both immature and mature soils.
We will further examine microstructure, diffraction

pattern, and elemental composition of specific regions
within the tested organo-mineral particles in this reportby transmission electron microscope (TEM) to discussorgano-mineral interactions.

Fig. 1. Carbon functional group map of immature soil
(Regosol). red: 284–286eV (aromatic C), blue: 286–
287 eV (phenol and aliphatic C), and green: 287–289
eV (amide and carboxyl C).

Fig. 2. Carbon functional group map of mature soil
(Andosol). red: 284–286eV (aromatic C), blue: 286–
287 eV (phenol and aliphatic C), and green: 287–289
eV (amide and carboxyl C).
[1] M. Asano et al., Soil Systems 2 (2018) 32.
[2] R. A. Dahlgren et al., Adv. Agron. 82 (2004) 113.
[3] M. Asano and R. Wagai, Geoderma 216 (2014) 62.

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STXM-XANES Analysis of Carbonaceous Matter in ~3.95 Billion-year-old
Sedimentary Rocks
M. Igisu1, T. Ohigashi2,3, H. Yuzawa2 and T. Komiya4

Department of Subsurface Geobiological Analysis and Research, Japan Agency for Marine-Earth Science andTechnology (JAMSTEC), Yokosuka 237-0061, Japan
2
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan3
School of Physical Sciences, The Graduate University for Advanced Studies (SOKENDAI), Okazaki 444-8585, Japan
4
Department of Earth Science and Astronomy, The University of Tokyo, Meguro 153-8902, Japan
1

Carbonaceous matter (CM) in Archean (approximately
4-2.5 billion years ago) sedimentary rocks provides
important insights into understanding the physiologicaland phylogenetic characteristics of life on early Earth [1].
The presence of life on Earth has been inferred primarily
from morphologically preserved microscopic fossils,
stromatolites, molecular biomarkers, and stable isotopic
compositions in sedimentary rocks. Recently, 13Cdepleted CM was found in ~3.95 billion-year-old
metasedimentary rocks in Labrador, Canada, which
provides the oldest evidence of life on Earth [2]. The
carbon isotopic signatures provide potential chemical
evidence of microbial activity in the environment at thetime. However, they do not necessarily offer clues for
distinguishing whether the products are derived from themicrobial functions of the bacterial and/or archaeal
populations. In this study, we characterized the molecular
structure of CM in order to obtain insights into its origin.
The C-K and N-K X-ray absorption near edge
structure (XANES) spectra of CM in sedimentaryrocks were acquired using a scanning transmission Xray microscope (STXM) at the BL4U, UVSOR.
Analyzed sedimentary rocks were a pelitic rock
(LAF497) and a conglomerate (LAD849A), bothcontaining CM. Before XANES analyses, Raman
microspectroscopic analysis was performed on the
petrographic thin sections to identify the presence ofCM and examine its graphitization degree [3]. The
Raman spectra revealed that the CM in the pelitic rock
was less graphitized as compared to that in theconglomerate. Thin cross-sectional foils (about 100150 nm thick) containing CM were then prepared byfocused ion beam (FIB) milling for thin sections ofboth peltic and conglomerate rocks.
Figure 1 shows an example of a C-XANES
spectrum of the CM in the conglomerate. Absorption
peaks at 285 eV and at 292 eV correspond to 1s → π*of electronic transitions in aromatic C=C bonds, and1s → σ* exciton of graphite, which are typical forgraphitized carbon [4]. The CM in the pelitic rock has
similar C-XANES spectra to that in the conglomerate,
regardless of the difference in their graphitization
degrees. N-XANES spectra for the CM did not exhibit
clear absorption peaks. Figure 2 reveals submicronscaled heterogeneity of carbon within one CM grain.
Although one possible explanation for thisheterogeneity is the orientation of the graphite layer,

further examination of the microstructure of the CM isrequired for further validation.

Fig. 1. Carbon-XANES(LAD849A).

spectrum of the CM

Ⅲ- 5

Fig. 2. A STXM image at 285 eV of the analyzed foil
(LAD849A).
[1] J. J. Brocks, Emerging Topics in Life Sciences 2(2018) 181.
[2] T. Tashiro et al., Nature 549 (2017) 516.
[3] O. Beyssac et al., J. Metamorph. Geol. 20 (2002)
859.
[4] G. D. Cody et al., Earth Planet. Sci. Lett. 272(2008) 446.

169
Ⅲ05- 15 -Ⅲ -5. Life, Earth and Planetary Sciences
BL4U
BL4U

3-Dimensional Spectroscopy of an Isolated Cell Nucleus by Using a
Scanning Transmission X-ray Microscope
2

Ⅲ- 5

T. Ohigashi1,2, H. Yuzawa1, S. Toné3, K. Shinohara4 and A. Ito4

UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
School of Physical Sciences, The Graduate University for Advanced Studies (SOKENDAI), Okazaki 444-8585, Japan
3
Graduate School of Advanced Science and Technology, Tokyo Denki University, Hatoyama 350-0394, Japan
4
School of Engineering, Tokai University, Hiratsuka 259-1292, Japan
1

Apoptosis is a programmed cell death which isfrequently observed in many biological processes such as
developmental process. Then, nuclear condensation and
DNA fragmentation occur during process of apoptosis,
and this process is classified into 3 stages regarding tomorphology of nucleus. Apoptosis is generally observedby using fluorescence microscope with staining process
but high resolution image, chemical compositions and 3dimensional (3D) structure of apoptosis are still unclear.
Then, scanning transmission X-ray microscopy (STXM)
with computer tomography (CT) is a promising tool toelucidate these issues with 3-dimensional (3D)
distribution of chemical states. In the previous report, we
performed STXM-CT of an isolated cell nucleus at N Kedge since DNA and protein have remarkable spectralfeatures at N K-edge [1]. However, qualities of 3D
distributions of DNA and protein were not good mainly
due to saturation of X-ray absorption [2]. In this report,
we tried STXM-CT of the cell nucleus by using O K-edge.
The isolated cell nucleus of HeLa S3 cell at stage 0 (i.e.
a normal cell) was used as a sample. After fixation by
glutaraldehyde, the cell nucleus was performed criticalpoint drying. The cell nucleus was glued on a tip of atungsten needle (TP-005, Micro Support Co., Ltd.) witha crystal bond and the tungsten needle was fixed on a CT
sample cell [3]. As data acquisition, 50 image stacks, eachof which is consisted of 48 STXM images around O Kedge region from 528 to 538 eV, were obtained manuallywith rotating the sample 3.6 each (in total 180 rotation)
to obtain complete projection data. Their measurement
conditions are as follows; scan area is 88 µm2 composedof 5050 pixels, and the dwell time is 1s per a pixel. Thismeasurement condition was determined to keep radiation
damage on the sample minimum.
As a pre-process of reconstruction, position shifts in
the image stacks were aligned and were converted to
optical density (OD) images by using aXis2000 program.
By extracting the OD images of same energies from each
image stack, sinograms were obtained. Cross-sectional
images were reconstructed from these sinograms byhome-made filtered-back projection algorithm.
3D reconstructed image (volume projection byusing ImageJ software) and, for an example, a crosssectional image of the isolated cell nucleus at the Xray energy of 528 eV are shown in Fig. 1. With
noticing structures of nucleoli and filaments, X-ray

absorption spectra are extracted from the areas in Fig.
1b (Fig. 2). Peaks of * resonance of the spectra(around 532 eV) resemble those of DNA and proteinin their position and shape.

(a)

(b)

2 µm

Fig. 1. (a) 3D volume projection image and (b) a crosssectional image of the isolated cell nucleus of the Xray energy of 528 eV.

529

531

533

535

Energy [eV]537

Fig. 2. Spectra extracted from reconstructed energy
stack. Colors of the spectra correspond to the areas
indicated in Fig. 1(b).
[1] T. Ohigashi, A. Ito, K. Shinohara, S. Tone, M. Kado,
Y. Inagaki, Y-F. Wang and N. Kosugi, AIP Conf. Proc.
1696 (2016) 020027.
[2] T. Ohigashi, A. Ito, K. Shinohara, S. Toné, Y.
Inagaki, H. Yuzawa and N. Kosugi, Microsc.
Microanal. 24 (2018) 400.
[3] T. Ohigashi, Y. Inagaki, A. Ito, K. Shinohara and N.
Kosugi, J. Phys.: Conf. Ser. 849 (2017) 012044.

170
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BL4U
BL4U

Study on the Mechanism of Microbial Weathering of Oceanic Crust byin situ Observation of the Basalt-cell Interface
S. Mitsunobu, S. Urano and J. Fukudo

Department of Agriculture, Ehime University, Matsuyama 790-8566, JapanThe weathering of oceanic basalts is one of the most
crucial water-rock interaction ubiquitously occurring in
the vast oceanic crust. The weathering of oceanic basalt
has a significant impact on Earth’s climate on ageological timescale by providing a sink foratmospheric CO2 through carbonization of oceanic
basalts [1]. The fresh basalt rock contains abundant Fe(about 10 wt.%) and its major species is ferrous iron(Fe(II)) and initial Fe(II)/Fetotal ratio in fresh basalt
ranges between 82 and 90% [2]. Hence, when theoceanic basalts are exposed to oxidative conditions, theFe(II) in basalts is gradually oxidized to Fe(III) in theweathering process on a geological timescale even at
low temperature in deep seafloor [3]. Recent previous
studies have reported that oceanic microorganisms(mainly bacteria) would play a significant role to theoxidation of Fe(II) in the basalt. Also, it is indicated thatbacterial Fe(II) oxidation would promote the whole
weathering process of oceanic crust [3], as the rate of
microbial Fe(II) oxidation is generally more rapid thanthat of chemical oxidation by dissolved O2. There havebeen considerable efforts to investigate chemical andbiological mechanism of the oxidation of Fe(II)involved in the oceanic basalt. However, little is known
on the mechanism of microbial Fe(II) in the basalt
alteration, because direct chemical speciations of Fe andbiomolecules at rock-microbe interface has beendifficult due to a short of spatial resolution in theanalysis.
Here, we examined the mechanisms of the Fe(II)oxidation in basalt weathering by using direct scanningtransmission X-ray microscopy (STXM)-based
NEXAFS analyses at UVSOR BL4U. The basalt
sample used in the study was prepared by in situ
incubation of fresh basalt glass for 12 months at deep
seafloor (water depth: 700-800 m) in Izu-Ogasawara
bonin.
STXM-based merged Fe/C image and C 1s NEXAFS
were shown in Fig. 1. The NEXAFS clearly showedthat the spectrum obtained at bacterial cell-basalt
interface (area 3) in the incubated basalt glass contains
a strong peak corresponding for acidic polysaccharides(alginate), addition to the other biomolecules of protein,
DNA, and lipid. The spectral features were notobserved in those of whole cell area. These finding
indicates that the sessile bacteria attached on the basalt
glass largely produced the polysaccharide-rich
extracellular polymeric substances at the cell-basalt
interface. The biogenic polysaccharides are likely toform a strong complex with Fe(II) under wide pH region[3]. Thus, our finding from C NEXAFS analysis

suggests that the sessile bacteria produce thepolysaccharides on the basalt glass to enhance thedissolution of basalt by the complexation between thecell and basalt surface. These findings would be an
important knowledge to understand mechanism ofbacteriogenic weathering of oceanic crust.

Ⅲ- 5

Fig. 1. STXM-based C and Fe images (upper) and C
1s NEXAFS spectra (bottom).
[1] H. Staugigel et al., Geochim. Cosmochim. Acta 53(1989) 3091.
[2] A. Bezos and E. Humler, Geochim. Cosmochim.
Acta 69 (2005) 711.
[3] W. Bach and K.J. Edwards, Geochim. Cosmochim.
Acta 67 (2003) 3871.

171
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BL4U
BL4U

Chemical Mapping of Individual Atmospheric Nanoparticles
R. R. Kamal1, J. J. Lin1, G. Michailoudi1, H. Yuzawa2, T. Ohigashi2 and N. L. Prisle1
Nano and Molecular Systems Research Unit, University of Oulu, Oulu 90041, Finland
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
1

2

Ⅲ- 5

Chemical maps were drawn for three types of aerosol
samples. 1) Laboratory-generated aerosols with 150 nm
diameter, produced by atomization of solutions of
sodium n-decanoate and sodium chloride with different
mixing ratios. 2) Urban aerosol samples collected in
Beijing during a winter campaign from October 2017 toJanuary 2018 jointly operated by Peking University andthe University of Gothenburg. Sampling was carried out
at the Peking University Atmosphere Environment
Monitoring Station on the roof of a six-floor building on
the campus of Peking University located in thenorthwestern urban area of Beijing. A SKC 4-stage
cascade impactor was used to collect particles with cutoff sizes of 250 and 500 nm that were impacted onto
Formvar films. 3) Plastic reference samples preparedfrom industrial grade plastics sliced as thinly as possible
to ensure good transmission of X-rays. Slices weremade of 100 and 60 nm polyethylene and 150 and 100
nm polypropylene using microtome. Spectra are to ourknowledge first of their kind and will serve as reference
for characterizing microplastic collected in nature.
Based on chemical formula, plastic samples should
only contain C-C bonds, and the absorption region from
280 to 320 eV was studied. Along with uniform
presence of expected C-C, as seen in selected region ofFig 1 (a), plastic samples also showed presence of K+
group. Occurrence of K was only around the sample
edges, indicating potential contamination during
cutting and slicing of the plastics. The spectrum in (c)also shows a small peak at 285 eV corresponding to
C=C [1], and further analysis is required to confirm
what contributes to that peak.
The urban aerosol samples were examined at theabsorption edges of carbon, nitrogen, sulfur, silicon,
chlorine, calcium, iron, vanadium, and titanium, toidentify their possible origins from e.g. organic sources,
mineral dust, or traffic emission. Figure 2 shows the
optical density of one particle probed at the carbon (a),sulfur (b), and calcium (c) edges and the spectra
obtained are shown in panels (d), (g), and (e)respectively. For comparison, panel (f) shows spectrafrom literature of laboratory-generated soot coated by
α-pinene (in red) and naphthalene SOA (in black) [2].
We did not observe similar peak features between 285
and 300 eV, but find peaks corresponding to K+ (296eV), sulfate (170-180 eV) and calcium (345-350 eV),suggesting that this particular particle examined most
likely originates from mineral dust. Other particles inthe same sample show indicators of different origins,comprising carbon, nitrogen, or heavy metal peaks.
Detailed analysis is required for more accurate
conclusions. Chemical mapping of single particles isstill extremely rare, and these experiments give a firstglimpse into the heterogeneity of samples previously
assumed to be uniform.
Laboratory-generated samples were mapped withfocus on spatially resolved chemical characterization.
Detailed analysis will reveal presence of biases insampling procedures.

Fig. 1. Optical density of plastic sample at various
photon energies. Bright areas indicate where excited
functional groups are located. (a) Regions with C-Cbonds; (b) Presence of K; (c) Spectra obtained fromselected regions showing peaks corresponding to of CC (288 eV), C=C (285 eV), and K (296 eV).

Fig. 2. Urban aerosol at different absorption edges andliterature reference of organic aerosol absorption spectra.
[1] R. C. Moffet, A.V. Tivanski and M.K. Gilles,
Fundamentals and Applications in Aerosol Spectroscopy(CRC Press; Boca Raton, Fl, 2011).
[2] J. C. Charnawskas et al., Faraday Discussions 200(2017) 165.

172
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BL4U
BL4U

STXM-XANES Analysis of Carbonaceous Matter of the Ediacara Biotatype Fossils from the Early Cambrian Chengjiang Section
T. Komiya1, T. Ohigashi2,3, D. Shu4, J. F. H. Cuthill5,6 and J. Han4

Department of Earth Science and Astronomy, The University of Tokyo, Meguro 153-8902, Japan
2
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan3
School of Physical Sciences, The Graduate University for Advanced Studies (SOKENDAI), Okazaki 444-8585, Japan
4
Early Life Institute & Department of Geology, Northwest University, 229 Taibai Road, Xi’an 710069, P.R. China
5
Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo 152-8550, Japan.
6
Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EQ, UK
1

The Ediacara biota is one of the enigmatic organismgroups through geologic history. The biota occurred in
the late Ediacaran from 580 to 543 Ma, namely during
the early evolution of the Metazoan. Their sizes andcomplexity indicate that they should be multi-cellularanimals, but it is still controversial which
phylum/phyla the Ediacara biota belong to. Seilacher(1989) proposed a new stem group of Vendobionta,
independent of all living-Metazoa. On the other hand,recent reappraisals suggest that each organism of the
Ediacaran biota should belong to a stem group of eachclosely-related phylum of the living organisms (e.g.
Xiao & Laflamme, 2009). Because some of the biota
have similar morphology to extant cnidarians andmolluscs, their classification into the phyla is plausible,
but most of them have quite different morphology
from the extant and even extinct Metazoa; thus theidentification does not work for most of them.
Generally speaking, each organism has its own
organic molecules, related to the function, such as
chitin and hemocyanin for arthropods and molluscs.
Therefore, detection of the unique organic molecules
is useful to identify the precursor organisms of thefossils. We tried detecting the organic molecules fromcarbonaceous matter (CM) in four Ediacara biota-type
fossils from the Chengjiang area, South China.
The C-K X-ray absorption near edge structure(XANES) spectra of the CM were acquired using ascanning transmission X-ray microscope (STXM) at
the BL4U, UVSOR. Raman microspectroscopic
analysis on the fossils was performed in order to
identify the CM before the XANES analyses.
Figure 1A shows four analytical points on an STXM
image of the Sample 4. Figure 1B shows C-XANES
spectra of the CM in the Sample 4 along with typical
spectra of chitin and collagen. The spectra are different
among the analytical points, suggesting that the CM isheterogeneous. The Chitin has two distinguishedpeaks at 285.1 and 288.56. The spectra of the sample
4, as well as other samples 1–3, are dissimilar to thoseof chitin and collagen. The absorption peaks around
285 eV and at 292 eV possibly correspond to 1s to π*of electronic transitions in aromatic C=C bonds, and1s to σ* exciton of graphite, respectively, which are
typical for graphitized carbon.
This study can detect neither chitin nor collagenfrom the Ediacara Biota-type fossils from South China.
Analysis of better-preserved specimen is required to
identify the precursor organisms from the fossils.

Ⅲ- 5Fig. 1. (A) Analytical points on Sample 4. (B) CarbonXANES spectra of the analytical points on the Sample
4 (A), and organic molecules of chitin and collagen.

173
Ⅲ05- 19 -Ⅲ -5. Life, Earth and Planetary Sciences
BL4B
BL4B

Preliminary Study on Nitrogen K-edge XANES on Martian Meteorites
R. Nakada1 and M. Koike2

Kochi Institute for Core Sample Research, Japan Agency for Marine-Earth Science and Technology(JAMSTEC), Nankoku 783-8502, Japan
2
Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA),
Sagamihara 252-5210, JapanⅢ- 5

Surface environment of terrestrial planet varies to alarge degree. The understanding on the diversity anduniversal property of planetary surface environment is
one of the most important study for the planetaryscience and is related to the habitability. Volatileelements such as hydrogen, carbon, and nitrogen
circulate through inner and surface of a planet anddetermine the evolution of the planetary environment.
However, the behavior and cycles of volatile elementsin the other planet than the Earth is largely unknown.
Mars had experienced a great environmental change;
it held a large body of liquid water on the surface in ~4
billion years ago, while presents a cold and dry
environment today [1]. This study focuses on thenitrogen on Mars and examines species and stable
isotope ratio (ratio between 15N and 14N) of nitrogen in
the Martian surface environment by analyzing theMartian meteorites.
In general, nitrogen in the planetary surface
circulates through (i) atmosphere, (ii) rocks, water, andbiosphere, and (iii) planetary interior by changing its
species. Modern atmospheric nitrogen (N2) on Mars is
0.15 mbar, though its 15N/14N ratio 1.6 times heavier
than the atmospheric N2 on the Earth [2]. Such a thinand heavy N2 can be a result of the atmospheric escape.
A model calculation suggests that the Mars had a dense
atmosphere in the past [3]. On the other hand, recent
exploration reported the presence of nitrate on theMartian surface [4]. Destructive analyses on impact
melt glass of Martian meteorites showed the presenceof nitrate with the remarkably lighter 15N/14N ratios
than Martian atmosphere [5, 6]. These studies suggest
the importance of the nitrogen fixation on Martiansurface environments. It is necessary to determine the15
N/14N ratios of individual nitrogen species tounderstand the Martian nitrogen cycle. However,
nitrogen abundance in Martian meteorites is typicallyaround 10 ppm [7, 8], which might be difficult todetermine the nitrogen species by X-ray absorption
near edge structure (XANES) analysis.
We have performed preliminary study on nitrogen
K-edge (402 eV) XANES measurements on Martian
meteorite at BL4B of UVSOR. NaNO3 and NH4Cl
reagents were measured in total electron yield mode,
while meteorites and epoxy resin were measured influorescence mode.
Small but clear X-ray absorption was observed forsome samples (Fig. 1). However, it should also be
noted that nitrogen X-ray absorption also occurs for

epoxy resin, which is generally used to make thinsection of a meteorite. In contrast, any absorption wasobserved from indium which is also used for sample
mounting. Regarding the nitrogen K-edge XANES
spectra of Martian meteorites, possible contribution ofcontaminant during preparation procedure should bechecked in future.

Normalized absorption

1

NaNO3

NH4Cl

Epoxy
IndiumMeteorite
Meteorite

390

400

410

420

Energy (eV)

430

440

Fig. 1. Nitrogen K-edge XANES spectra of standards
and samples.
[1] V. R. Baker, Nature 412 (2001) 228.
[2] M. H. Wong et al., Geophys. Res. Lett. 40 (2013)6033.
[3] H. Kurokawa et al., Icarus 299 (2018) 443.
[4] J. C. Stern et al., PNAS 112 (2015) 4245.
[5] M. M. Grady et al., J. Geophys. Res. 100 (1995)
5449.
[6] S. P. Kounaves et al., Icarus 229 (2014) 206.
[7] Y. N. Miura et al., GCA 59 (1995) 2105.
[8] K. Mathew and K. Marti, J. Geophys. Res. 106(2001) 1401.

174
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BL5B
BL5B

Evaluation of the Hydrogen Absorption Cell Imager
for Planetary Explorations
Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Sagamihara 252-5210, Japan
2
College of Science, Rikkyo University, Tokyo 171-8501, Japan
3
Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8561, Japan
4
Faculty of Engineering, Shinshu University, Nagano 380-8553, Japan

In the planetary lower atmosphere, H2O generate
mainly hydrogen atoms through photodissociation by
sunlight. The generated hydrogen atoms ascend to the
exopause and only those atoms which have higher
kinetic energy than gravitational potential energy there
escape to interplanetary through thermal dissipation.
Understanding the dissipation process in the present
environment gives us some information to estimate
planetary atmospheric evolution.
Hydrogen atoms in the planetary exosphereresonantly scatter the solar H Lyman-alpha radiation(121.567 nm) and form the planetary hydrogen corona.
Imaging of this emission gives us to obtain the spatial
structure of the corona because its brightness depends
on the number density of the hydrogen atoms.
An absorption cell technique is efficient for remotesensing for the density and temperature distributionsof the exospheric hydrogen atoms in the planet. In
addition, the absorption cell technique has someadvantages over others from the point of view ofgeometrical size, weight, simplicity, and durability.
Thus, the technique is suitable for future missions withsmall size spacecraft.
An absorption cell photometer was mounted on thefirst Japanese Mars mission [1, 2], NOZOMI, but theparameter optimization for the absorption cell wasinsufficient due to the limitation of the developmenttime. Therefore, further optimization and study havebeen required for future space missions. We evaluatedthe performances which depend on filament shape,
applied power to the filament, enclosed gas pressure,
optical path length of the cell, and position of theincident light using an ultra high resolution Fouriertransform spectrometer installed on the DESIRS
beamline of Synchrotron SOLEIL in France in 2016
and 2018. However, additional evaluations of theperformances, such as an endurance test of thefilaments, confirmation of absorption stability, havebeen needed. See Kuwabara et al. [2018] for moredetails [3].
In this experiment, we evaluate the stability of theabsorption performance of the cell using the SOR
beam with high intensity and stability. Figure 1 shows
the configuration of the experiment. A prototype ofhydrogen absorption cell imager consists of anabsorption cell, MgF2 band-pass filter, and photon
detector. Microchannel plates and a resistive anodeencoder are assembled and used as the photon detector.
The absorptance of the cell for the hydrogen Lymanalpha radiation (121.567 nm) is measured with a repeatof turning on and off filaments at 0.3 Hz throughapproximately 60 hours.
The result is shown in Fig. 2. The absorptance seems
to be stable and its value is 4.95% ± 0.92. The errors
are caused by the measurement system. For the next
step, further long-term stability should be investigated.

Fig. 1. Photo of the prototype of the new imager.
87
Absorptance [%]1

M. Kuwabara1, M. Taguchi2, K. Yoshioka3, T. D. Kawahara4, S. Kameda2,
S. Komoriya2, S. Yonemoto3, Y. Shirafuji2 and S. Kawase2

6
5
4
3
2
5

10

15
20
25
Energization time [hour]

30

Fig. 2. Temporal variation of the absorptance of the
prototype of the new imager.
[1] T. D. Kawahara et al., Applied Optics 36 (1997)2229.
[2] M. Taguchi et al., Earth, Planets and Space 52(2000) 49.
[3] M. Kuwabara et al., Rev. Sci. Instrum. 89 (2018)023111.

175
Ⅲ05- 21 -Ⅲ- 5

Ⅲ -5. Life, Earth and Planetary Sciences
BL7B
BL7B

Effect of Space Weathering on Identification of Organic Matter on Celestial
Body Surface Using Ultraviolet Wavelength Region Spectrum
S. Arao1, I. Yoshikawa1,2, K. Yoshioka1,2, I. Sakon3, R. Hikida1, R. Katsuse2 and I. Endo3

Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo,
Tokyo 113-0033, Japan2
Department of Complexity Science and Engineering, Graduate School of Frontier Sciences, The University ofTokyo, Chiba 277-8561, Japan3
Department of Astronomy, Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan1

Ⅲ- 5

Analysis of reflection spectrum is a conventional
means for identifying compositions of the celestialbody’s surface, but in the ultraviolet region, it has
rarely been conducted. Analysis of spectrum suggests
the existence of polycyclic aromatic hydrocarbon(PAH) in interstellar dust and on the surface of Mars’moon Phobos, but the replication study is insufficient.
A comparison of the spectra of natural terrestrial PAH
mixtures with that of interstellar dust or the Phobos
surface suggests that there are similarly shaped
absorption bands around wavelengths of 210 nm and
217.5 nm respectively. This similarity is the basis of
the hypothesis that PAH is present in interstellar dust
and the Phobos surface. However, considering the gapof peak wavelength, there are also many negative
opinions on the hypothesis. Thus, there has been no
definitive conclusion until now.
One of the phenomena that may have a description
for this problem is change in the absorption spectrum
due to space weathering. The absorption band of PAH
around the wavelength of 210 nm is caused by thetransition of aromatic π electrons and their orbital area
relates to the absorption peak wavelength. If thehydrogen atoms bonded to the aromatic rings of PAH
molecules are desorbed by space weathering, it issuggested theoretically that the orbital area of aromatic
π electrons is broadened and the absorption band’s
peak wavelength may approach 217.5 nm.
In this experiment, to evaluate the influence of
space weathering on the optical properties of PAH, weprepared several PAH (coronene and chrysene)
samples which had been exposed to the spaceenvironment for about 1 year on orbit of theInternational Space Station (ISS). Then, we compared
the reflection characteristics of these samples withthose of non-exposure samples in a wavelength regionof 160-300 nm.
As a result, all the samples experienced space
weathering reflected the light in 160-300 nm
wavelength region more weekly than non-exposure
samples did. Furthermore, reflection characteristics ofcoronene sample exhibited a broad dip around 235 nm
wavelength and showed a trend in 210-280 nm
wavelength region that the attenuation of the reflected
light is more significantly at longer wavelengths (Fig.
1). This trend suggests that the wavelength whichcorresponds to the bottom of the dip may shift to thedirection of longer wavelength due to space
weathering.
As another research, to detect the main factor ofspace weathering, we are going to irradiate nonexposure PAH samples with UV light or radial ray
simulating the environment on the flight orbit of theISS, and compare their reflection characteristics withthose of space weathered sample.

Fig. 1. Reflection characteristics of coronene sample
in a wavelength region of 160-300 nm. Each curveshows an average of measured values upon threedifferent incident points on the sample. Typical errors
are added on the plots at 300 nm wavelength.
[1] Bertaux et al., Proceedings of the EPSC-DPS Joint
Meeting. 2011.
[2] Hendrix et al., Meteoritics & Planetary Science 51(2016) 105.
[3] Joblin et al., The Astrophysical Journal 393 (1992)
L79.
[4] Sakata et al., Nature 301 (1983) 493.
[5] Steglich et al., The Astrophysical Journal 742 (2011)2.

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