MARUO Masahiro




Research Fields, Keywords

Aquatic Chemistry, Analytical Chemistry

Mail Address

E-mail address

Graduating School 【 display / non-display

  • Kyoto University  Faculty of Science  1988.03

Graduate School 【 display / non-display

  • Kyoto University  Graduate School, Division of Natural Science  Doctor's Course  1994.03

Campus Career 【 display / non-display

  • University of Shiga Prefecture  School of Environmental Science  Department of Ecosystemus Studies  Professor   2016.04 - Now

  • University of Shiga Prefecture  School of Environmental Science  Department of Ecosystemus Studies  Associate Professor   2007.11 - 2016.03

  • University of Shiga Prefecture  School of Environmental Science  Department of Ecosystemus Studies  Lecturer   2005.09 - 2007.10

  • University of Shiga Prefecture  School of Environmental Science  Department of Ecosystemus Studies  Research Assistant   1995.04 - 2005.08

External Career 【 display / non-display

  • Graduate School of Human and Environmenral Studies, Kyoto University  Special researcher of the Japan Society for the Promotion of Science   1994.04 - 1995.03

  • Department of Earth and Ocean Sciences, Faculty of Science, The University of British Columbia  Visiting Scientist   2003.06 - 2003.11

Academic Society Affiliations 【 display / non-display

  • Japanese Society of Limnology

  • Japanese Society of Analytical Chemistry

  • International Socity of Limnology (SIL)

Field of expertise (Grants-in-aid for Scientific Research classification) 【 display / non-display

  • Meteorology/Physical oceanography/Hydrology

  • Analytical chemistry

  • Environmental dynamic analysis

  • Geochemistry/Cosmochemistry


Papers 【 display / non-display

  • Differences in dissolved phosphate in shallow-lake waters as determined by spectrophotometry and ion chromatography

    Yi R., Song P., Liu X., Maruo M., Ban S.

    Limnology  Limnology    2019.04

    10.1007/s10201-019-00574-2  Joint Work  


    © 2019, The Japanese Society of Limnology. Phosphorus (P) plays important roles in aquatic ecosystems, but accurately determining phosphorus species (particularly bioavailable phosphate) is difficult. When phosphate concentrations are spectrophotometrically measured as soluble reactive P (SRP), the actual values are often overestimated. Ion chromatography is one method for accurately measuring orthophosphate concentrations. To clarify how the spectrophotometrical measurement overestimates actual phosphate concentrations, we compared estimates of phosphate concentrations in lake waters using both methods. SRP and orthophosphate concentrations in water samples collected from four shallow lakes around Lake Biwa, Japan, were determined monthly for 1 year by spectrophotometry and ion chromatography, respectively. SRP concentrations were frequently higher than those for orthophosphate in all lakes throughout the study period, suggesting that SRP and orthophosphate are not equivalent, although a significant relationship was found between them. Orthophosphate/SRP (ortho/SRP) ratios varied spatiotemporally in all lakes (range 0.11–1.04; mean 0.56), being well predicted by biological-mediated relevant parameters using a stepwise multiple logistic regression analysis (R 2 = 0.76). The results implied that organic matter associated with biological activity contributes to the variability in ortho/SRP ratios. Such large variability in ortho/SRP ratios emphasizes the importance of accurate orthophosphate estimates for understanding P dynamics in aquatic ecosystems.

  • Determination of trace methylphosphonate in natural waters by ion chromatography

    Tsuji K, Maruo M, Obata H

     68 (4)   275 - 278  2019.04

    10.2116/bunsekikagaku.68.275  Joint Work  

  • Determination of dissolved and particulate thiols in Lake Biwa water and extracted fulvic acids by solid phase extraction followed by HPLC with fluorescence detection

    Rasheduzzaman M., Kawaguchi M., Obata H., Maruo M.

    Limnology  Limnology  19 (3)   299 - 309  2018.08

    10.1007/s10201-018-0547-1  Joint Work  


    © 2018, The Japanese Society of Limnology. Thiols are important antioxidants that can modulate the bioavailability and biogeochemistry of many soft metals, although their detection remains challenging in both their reduced (R–S) and oxidized (R–S–S–R) forms. Here, a modified biochemical method was applied to determine the levels of dissolved and particulate thiols in Lake Biwa water and extracted Lake Biwa fulvic acids obtained at various depths. This method involves the use of the reducing agent tris(2-carboxyethyl)phosphine and the fluorescent label 7-fluorobenzofurazan-4-sulfonic acid ammonium salt (SBD-F), followed by solid-phase extraction and HPLC with fluorescence detection. Dissolved cysteine (Cys) (2.0–6.0 nM), glutathione (GSH) (2.8–5.1 nM), and N-acetyl-l-cysteine (NAC) (1.6–4.2 nM) were detected throughout the water column but were broadly consistent at depths of 5–20 m. In contrast, abundant levels of particulate cysteine (1.3–3.5 × 102nM) and glutathione (1.6–3.1 × 102nM) were detected down to depths of 15 m. The particulate cysteine and glutathione were significantly covariant, and the ratios between them reflected the differences in the plankton community composition and availability of these compounds. This work also studied the concentrations of Cys, GSH and NAC in Lake Biwa fulvic acids (LBFAs) for the first time (at 0 m: cysteine, 0.8 nM; glutathione, 1.6 nM; NAC, 2.5 nM; at 10 m: cysteine, 1.4 nM; glutathione, 0.6 nM; NAC, 1.6 nM). The nanomolar to sub-nanomolar concentrations of the particulate and dissolved Cys, GSH and NAC in the lake indicates that these are an important class of ligands for chalcophile metals and may influence the distribution of plankton communities from the epilimnion to the hypolimnion of the lake.

  • Assessment of the Status of Groundwater Arsenic at Singair Upazila, Manikganj Bangladesh; Exploring the Correlation with Other Metals and Ions

    Md. Mostafizur Rahman, Rebeka Sultana, Mashura Shammi, Joti Bikash, Tanveer Ahmed, Masahiro Maruo, Masaaki Kurasaki, M. Khabir Uddin

    Springer  Exposure and Health  8 (2)   217 - 225  2016.02

    10.1007/s12403-016-0196-8  Joint Work  Joint(The vice charge)

  • Trace elements influenced by environmental changes in Lake Biwa: (I) Seasonal variations under suboxic hypolimnion conditions during 2007 and 2009

    Yusuke Nakashima, Akiyoshi Shimizu, Masahiro Maruo, Yoshiki Sohrin

    Springer  Limnology  17 (2)   151 - 162  2016.01

    10.1007/s10201-015-0474-3  Joint Work  Joint(The vice charge)

  • Trace elements influenced by environmental changes in Lake Biwa: (II) Chemical variations in the hypolimnion over the last half-century

    Yoshiki Sohrin, Yusuke Nakashima, Masahiro Maruo

    Springer  Limnology  17 (2)   163 - 173  2016.01

    10.1007/s10201-015-0477-0  Joint Work  Joint(The vice charge)

  • Comparison of soluble reactive phosphorous and orthophosphate concentrations in river waters

    Masahiro Maruo, Mana Ishimaru, Yuma Azumi, Yuki Kawasumi, Osamu Nagafuchi, Hajime Obata

    Springer  Limnology  17 (1)   7 - 12  2015.12

    10.1007/s10201-015-0463-6  Joint Work  Joint(The main charge)

  • Determination of aquatic humic substances in Japanese lakes and wetlands by the carbon concentration-based resin isolation technique

    Kumiko Tsuda, Morimaru Kida, Suzuka Aso, Taku Kato, Nobuhide Fujitake, Masahiro Maruo, Kazuhide Hayakawa, Mitsuru Hirota

    Springer  Limnology  17 (1)   1 - 6  2015.12

    10.1007/s10201-015-0455-6  Joint Work  Joint(The vice charge)

  • Annual layers in river-bed sediment of a stagnant river-mouth area of the Kitagawa Brook, Central Japan

    Yoshimasa Kurashige, Toshiaki Nakano, Eri Kasubuchi, Masahiro Maruo, Hanako Domitsu

    IAHS Publishing  IAHS-AISH Proceedings and Reports: International Symposium on Sediment Dynamics: From the Summit to the Sea, ICCE 2014; Astor Crowne PlazaNew Orleans; United States; 11 December 2014 through 14 December 2014; Code 115823  367   251 - 257  2014.12

    Joint Work  Joint(The vice charge)

  • Environmental Education in a Lagoon Naiko "Nishinoko", connected with Lake Biwa

    Mitamura O, Ishikawa S, Ishida N, Goto N, Tachibana J, Maruo M

     Limonological Study  1 (1)   5 - 15  2014.07

    Joint Work  Joint(The vice charge)

display all >>

Books 【 display / non-display

  • The Geology, Biodiversity and Ecology of Lake Hovsgol (Mongolia)

    C. E. Goulden, T. Sitnikova, J. Gelhaus, B. Boldgiv編:熊谷道夫、占部城太郎、CE Goulden、D Hadbaatar、辻村茂男、速水祐一、関野樹、丸尾雅啓、B. Boldgiv、N. Soninkhshig ほか

    Backhuys Publishers, Leiden, Nederland  526p  2006.02

    Scholarly Book  Joint Work

  • Marine Environment: The Past, Present and Future

    Chen-Tung Arthur Chen編、著者:中山英一郎、丸尾雅啓ほか多数

    Fuwen Press, Kaohsiung, Taiwan  516p  2002.09

    Scholarly Book  Joint Work

Review Papers 【 display / non-display

  • Metal speciation in inland waters

    Masahiro Maruo

    Institute of Oceanochemistry  Transactions of The Institute of Oceanochemistry  28 (1)   2 - 9  2015.04

     Single Work  

  • Chemical analysis of metal complexing ligands in natural waters

    Masahiro Maruo

    Japan Society for Analytical Chemistry  Bunseki  * (470)   71 - 75  2014.02

     Single Work  

Conferences 【 display / non-display

  • Determination of Trace Methylphosphonate in Freshwater by Ion Chromatography

    SIL 34th International Congress (International Society of Limnology)  2018.08

  • Determination of Dissolved and Particulate Thiols in Lake Biwa Water and Extracted Fulvic Acid by HPLC-Fluorescence Detection with SPE

    3rd SUT-USP Joint Symposium on Environmental Science  2017.12

  • Development of analytical methods for chemical speciation of nutritious elements

    2nd SUT-USP Joint Symposium on Environmental Science  2017.02

  • Comparison between soluble reactive phosphorus and orthophosphate concentrations in lake waters

    The 17th International Symposium on River and Lake Environments (ISRLE2014)  2017.03

  • Determination of nanomolar levels of phosphate in water of P-limited lake in Japan (Lake Biwa) bu ion chromatography

    SIL2016 (33rd SIL Congress)  2016.08

  • Investigation of highly strong copper complexing ligands in lake water by peudopolarography

    The 15th International Symposium on River and Lale Environments,  2012.10

  • Optical Characteristics and Molecular Weight Distributions of Whole Natural Organic Matter in Lake BIWA and Other Freshwater Systems in Japan - An Indication of NOM Sources and Speciation

    ASLO Aquatic Science Meeting 2012  2012.07

  • Comparison of Determination Methods of Iron(II) in Freshwater of Lake Biwa, Japan, in Consideration of Organic Complexation

    ASLO Aquatic Science Meeting 2012  2012.07

  • Azo Dye Binding Interactions with Freshwater and Treated Wastewater Dissolved Organic Matter

    Sixth International Conference on Environmental Science and Technology  2012.06

  • Binding Interaction of 1-Napthol with the Dissolved Organic Matter of Lake Biwa and Treated Sewage Wastewater: A Comparative Analysis based on UV-Visible and Fluorescence Characteristics

    International Conference on Environmental Pollution and Remediation, ICPER2011  2011.08

display all >>