I'm utilizing various analytical methods of organic geochemistry and isotope geochemistry, via instruments both in our lab in LBERI and in nearby labs of my collaborators.

Microbial contribution to detrital organic matter pools (DOM & POM) can be assessed by analysis of abundance and compositions of various microbial biomolecules (e.g., D-amino acids, amino sugars).

Instruments for these analysis include

(1) HPLC (High-Performance Liquid Chromatography) for analysis of organic compounds (amino acids, etc). We have two HPLC systems at LBERI: (1) Agilent 1260 system equipped with a fluorescence detector (FLD) and a diode array detector (DAD) and (2) Agilent 1100 system equipped with a variable wavelength detector (VWD), a charged aerosol detector (CAD), and a fraction collector. We are using the first one for quantification of organic compounds (mainly amino acid composition and enantiomers), and the second one mainly for purification of organic compounds (mainly amino acids) for further analytical works (e.g., compound-specific isotope analysis).

(2) GC-qMS (Gas Chromatography Quadrupole Mass Spectrometer) for quantification of organic compounds (amino acids, lipids, sugars, etc), at RIHN (collaboration with Ichiro Tayasu, Chikage Yoshimizu) and at CER, Kyoto Univ. (collaboration with Keisuke Koba).

Characterization of chemical and physical properties of organic matter (composition, optical properties, molecular size distribution, etc.) in natural environments is crucial to understand its biogeochemical dynamics.

Instruments for these analysis include

(1) Fluorometer for 3D-EEM analysis of CDOM & FDOM

(2) HPSEC-TOC (High-Performance Size Exclusion Chromatography coupled with TOC analyzer) for quantification of DOM molecular size distribution, at NIES Lake Biwa Branch Office (collaboration with Koichi Shimotori, Akio Imai)

Isotopic composition (e.g., 15N/14N, 13C/12C) at natural abundance level can be powerful indicators of sources and cycling of organic matter in natural environments. I have been utilizing various methods including compound-specific nitrogen isotope analysis of amino acids. Our lab in LBERI is not equipped with isotope ratio mass spectrometers, but I'm collaborating with various researchers in nearby research institutes.

Instruments for these analysis include

(1) GC-C-IRMS (Gas Chromatography - Combustion - Isotope Ratio Mass Spectrometer) for compound-specific isotope analysis of organic compounds, at RIHN (collaboration with Ichiro Tayasu, Chikage Yoshimizu) and at CER, Kyoto Univ. (collaboration with Keisuke Koba).

(2) PT-GC-IRMS (Purge & Trap GC-IRMS) for small-scale nitrogen isotope analysis by the denitrifier method, at CER, Kyoto Univ. (collaboration with Keisuke Koba).

(3) EA-IRMS (Elemental Analyzer - Isotope Ratio Mass Spectrometer) for bulk C & N isotope analysis, at CER, Kyoto Univ. (collaboration with Keisuke Koba) and at NIES (collaboration with Ayato Kozu).

(4) GC-qMS & EA-IRMS for stable isotope labeling analysis at CER, Kyoto Univ. (collaboration with Keisuke Koba). We are planning to develop a method for 15N-SIP of D-amino acids in DOM.

We are currently working on developing facilities for isolation of various size classes of organic matter (both DOM & POM) from water samples, such as ultrafiltration (UF), nanofiltration (NF), reverse-osmosis (RO), electrodialysis (ED), solid phase extraction (SPE), etc.

Our lab in LBERI is equipped with various facilities for biogeochemical analysis and experiments.

(1) TOC analyzer for DOC concentration analysis

(2) Ion chromatography for analysis of anions & cations

(3) Elemental analyzer for POC/PN concentration analysis

(4) Spectrophotometer for colorimetric analysis

(5) FRRF (Fast Repetition Rate Fluorometry) for measuring primary production of phytoplankton

etc

Our lab in LBERI is also equipped with various facilities for field sampling.

(1) R/V Biwakaze for field sampling in Lake Biwa

(2) CTD rosette mounted with 5L niskin bottles (x 10) for sampling of lake water from discrete depths

(3) GoFlo water sampler (100 L) for large-scale sampling of lake water

(4) Sediment core sampler

etc