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Application of Fluorescence Excitation Emission Matrices for Diagnosis and Source Identification of Watershed Pollution : A Review

유기물 형광분석법을 활용한 유역 오염 진단 및 오염원 추적: 문헌 연구

  • Kandaddara Badalge Nipuni Dineesha (Department of Advanced Science and Technology Convergence, Kyungpook National University) ;
  • Jin Hur (Department of Engineering Environment, Energy and Geoinformatics, Sejong University) ;
  • Byung Joon Lee (Department of Advanced Science and Technology Convergence, Kyungpook National University)
  • Received : 2022.10.16
  • Accepted : 2022.12.28
  • Published : 2023.01.30

Abstract

The constituents of a watershed control a wide range of ecosystem processes, such as, carbon sequestration, nutrient retention, and biodiversity preservation. Maintenance of a healthy watershed is advantageous to humans in many direct and indirect ways. Dissolved organic matter fluorescence analysis is one of the most commonly utilized parameters for water quality measurement, pollution source tracking, and determination of the ecological state of a watershed. Throughout the recent decades, the advancement in data processing, instrumentation, and methods has resulted in many improvements in the area of watershed study with fluorescence analysis. The current trend of coupling advanced instrumentations and new comparative parameters, such as, microplastics of different types, antibiotics, and specific bacterial contaminants have been reported in watershed studies. However, conventional methodologies for obtaining fluorescence excitation emission matrices and for calculating the fluorescence and spectral indices are preferred to advanced methods, due to their easiness and simple data collection. This review aims to gain a general understanding of the use of dissolved organic matter fluorescence analysis for diagnosis and source identification of watershed pollutions, by focusing on how the studies have utilized fluorescence analysis to improve existing knowledge and techniques in recent years.

Keywords

Acknowledgement

This work was supported by the Korea Environment Industry & Technology Institute (KEITI) through the Program for the Management of Aquatic Ecosystem Health, funded by the Korea Ministry of Environment (MOE) (No. 2020003030005).

References

  1. Allan, J. D. (1995). Stream ecology: Structure and function of running waters, Springer Nature, Dordrecht, the Netherlands.
  2. Andrade-Eiroa, A., Canle, M., and Cerda, V. (2013). Environmental applications of excitation-emission spectrofluorimetry: An in-depth review II, Applied Spectroscopy Reviews, 48(2), 77-141. https://doi.org/10.1080/05704928.2012.692105
  3. Arguelho, M. de L. P. de M., Alves, J. do P. H., Monteiro, A. S. C., and Garcia, C. A. B. (2017). Characterization of dissolved organic matter in an urbanized estuary located in Northeastern Brazil, Environmental Monitoring and Assessment, 189(6), 272.
  4. Ayeni, T. T., Iwamoto, Y., Takeda, K., Sakugawa, H., and Mostofa, K. M. G. (2022). Optical properties of dissolved organic matter in Japanese rivers and contributions to photoformation of reactive oxygen species, Science of the Total Environment, 826(20), 153-671. https://doi.org/10.1016/j.scitotenv.2022.153671
  5. Baker, A. (2001). Fluorescence excitation - Emission matrix characterization of some sewage-impacted rivers, Environmental Science and Technology, 35(5), 948-953. https://doi.org/10.1021/es000177t
  6. Band, L. E., Hwang, T., Hales, T. C., Vose, J., and Ford, C. (2012). Ecosystem processes at the watershed scale: Mapping and modeling ecohydrological controls of landslides, Geomorphology, 137(1), 159-167. https://doi.org/10.1016/j.geomorph.2011.06.025
  7. Bhattacharya, R. and Osburn, C. L. (2020). Spatial patterns in dissolved organic matter composition controlled by watershed characteristics in a coastal river network: The Neuse river basin, USA, Water Research, 169(1), 115248.
  8. Bolan, N. S., Adriano, D. C., Kunhikrishnan, A., James, T., McDowell, R., and Senesi, N. (2011). Dissolved organic matter. Biogeochemistry, dynamics, and environmental significance in soils, Advances in Agronomy, 110(c), 11-26. https://doi.org/10.1016/B978-0-12-385531-2.00001-3
  9. Bro, R. (1997). PARAFAC. Tutorial and applications, Chemometrics and Intelligent Laboratory Systems, 38(2), 149-171. https://doi.org/10.1016/S0169-7439(97)00032-4
  10. Chaves, R. C., Figueredo, C. C., Boechat, I. G., de Oliveira, J. T. M., and Gucker, B. (2020). Fluorescence indices of dissolved organic matter as early warning signals of fish farming impacts in a large tropical reservoir, Ecological Indicators, 115, 106-389. https://doi.org/10.1016/j.ecolind.2020.106389
  11. Chen, Y., Senesi, N., and Schnitzer, M. (1977). Information provided on humic substances by E4/E6 ratios, Soil Science Society of America Journal, 41(2), 352-358 https://doi.org/10.2136/sssaj1977.03615995004100020037x
  12. Chen, Z., Doering, P. H., Ashton, M., and Orlando, B. A. (2015). Mixing behavior of colored dissolved organic matter and its potential ecological implication in the Caloosahatchee river estuary, Florida, Estuaries and Coasts, 38(3), 1706-1718. https://doi.org/10.1007/s12237-014-9916-0
  13. Chen, Z., Hu, C., Conmy, R. N., Muller-Karger, F., and Swarzenski, P. (2007). Colored dissolved organic matter in Tampa bay, Florida, Marine Chemistry, 104, 15-21. https://doi.org/10.1016/j.marchem.2006.12.007
  14. Clayton J., W., Paul C., F., Ana M. Morales, W., James H., L., William B., R., Aisha S., C., and Marguerite A. X. (2017). Human activities cause distinct dissolved organic matter composition across freshwater ecosystems, World Aquaculture Society, 51(2), 909-926.
  15. Clipp, H. L. and Anderson, J. T. (2014). Environmental and anthropogenic factors influencing salamanders in riparian forests: A review, Forests, 5(11), 76-89. https://doi.org/10.3390/f5112679
  16. Coble, P. G. (1996). Characterization of marine and terrestrial DOM in seawater using excitation-emission matrix spectroscopy, Marine Chemistry, 51(4), 325-346. https://doi.org/10.1016/0304-4203(95)00062-3
  17. Coble, P. G. (2007). Marine optical biogeochemistry: The chemistry of ocean color, Chemical Reviews, 107(2), 114-156. https://doi.org/10.1021/cr050350+
  18. Coble, P. G., del Castillo, C. E., and Avril, B. (1998). Distribution and optical properties of CDOM in the Arabian sea during the 1995 southwest monsoon, Deep-Sea Research Part II: Topical Studies in Oceanography, 45(2), 10-11. https://doi.org/10.1016/S0967-0645(98)00068-X
  19. Coble, P. G., Green, S. A., Blough, N. V., and Gagosian, R. B. (1990). Characterization of dissolved organic matter in the Black sea by fluorescence spectroscopy, Nature, 348, 432-435. https://doi.org/10.1038/348432a0
  20. Coble, P. G., Spencer, R. G. M., Baker, A., and Reynolds, D. M. (2014). Aquatic organic matter fluorescence, Cambridge University Press, Cambridge, UK, 75-122.
  21. Conmy, R. N., del Castillo, C. E., Downing, B. D., and Chen, R. F. (2014). Experimental design and quality assurance in aquatic organic matter fluorescence, Cambridge University Press, Cambridge, UK, 190-230.
  22. Cory, M. R., Matthew, P. M., McKnight, M. D., and Guerard, J. J. (2010). Effect of instrument-specific response on the analysis of fulvic acid fluorescence spectra, Limnology and Oceanography: Methods, 56(6), 146-161.
  23. Cory, R. M. and McKnight, D. M. (2005). Fluorescence spectroscopy reveals ubiquitous presence of oxidized and reduced quinones in dissolved organic matter, Environmental Science and Technology, 39(21), 8142-8149. https://doi.org/10.1021/es0506962
  24. D'Andrilli, J., Silverman, V., Buckley, S., and Rosario-Ortiz, F. L. (2022). Inferring ecosystem function from dissolved oganic matter optical properties: A critical review, Environmental Science and Technology, 56(16), 11146-11161. https://doi.org/10.1021/acs.est.2c04240
  25. del Vecchio, R. and Blough, N. V. (2002). Photobleaching of chromophoric dissolved organic matter in natural waters: Kinetics and modeling, Marine Chemistry, 78(4), 231-253. https://doi.org/10.1016/S0304-4203(02)00036-1
  26. Derrien, M., Brogi, S. R., and Goncalves-Araujo, R. (2019). Characterization of aquatic organic matter: Assessment, perspectives and research priorities, Water Research, 163(15), 114908.
  27. DeVilbiss, S. E., Zhou, Z., Klump, J. V., and Guo, L. (2016). Spatiotemporal variations in the abundance and composition of bulk and chromophoric dissolved organic matter in seasonally hypoxia-influenced Green bay, lake Michigan, USA, Science of the Total Environment, 565(15), 742-757. https://doi.org/10.1016/j.scitotenv.2016.05.015
  28. Edzwald, J. K., Becker, W. C., and Wattier, K. L. (1985). Surrogate parameters for monitoring organic matter and THM precursors, Journal of American Water Works Association, 77(4), 122-132. https://doi.org/10.1002/j.1551-8833.1985.tb05521.x
  29. Gabor, R. S., Baker, A., McKnight, D. M., and Miller, M. P. (2014). Fluorescence indices and their interpretation. Aquatic organic matter fluorescence, Cambridge University Press, Cambridge, UK, 303-338.
  30. Gilchrist, J. R. and Reynolds, D. M. (2014). Optical spectroscopy instrumentation design, quality assurance, and control. Aquatic organic matter fluorescence, Cambridge University Press, Cambridge, UK, 147-189.
  31. Graeber, D., Gelbrecht, J., Kronvang, B., Gucker, B., Pusch, M. T., and Zwirnmann, E. (2012). Technical Note: Comparison between a direct and the standard, indirect method for dissolved organic nitrogen determination in freshwater environments with high dissolved inorganic nitrogen concentrations, Biogeosciences Discuss, 9(11), 7021-7048. https://doi.org/10.5194/bg-9-4873-2012
  32. Grimm, N. B., Foster, D., Groffman, P., Grove, J. M., Hopkinson, C. S., Nadelhoffer, K. J., Pataki, D. E., and Peters, D. P. C. (2008). The changing landscape: Ecosystem responses to urbanization and pollution across climatic and societal gradients, Frontiers in Ecology and the Environment 6 (5), 67-80. https://doi.org/10.1890/1540-9295(2008)6[67:TAR]2.0.CO;2
  33. Gu, L., Tang, X., Sun, Y., and Kou, H. (2020). Bioavailability of dissolved organic matter in biogas slurry enhanced by catalytic ozonation combined with membrane separation, Ecotoxicology and Environmental Safety, 196(5), 167-214. https://doi.org/10.1016/j.ecoenv.2020.110547
  34. Guo, L., White, D. M., Xu, C., and Santschi, P. H. (2009). Chemical and isotopic composition of high-molecular-weight dissolved organic matter from the Mississippi River plume, Marine Chemistry, 114(2), 3-4. https://doi.org/10.1016/j.marchem.2009.04.002
  35. Helms, J. R., Stubbins, A., Ritchie, J. D., Minor, E. C., Kieber, D. J., and Mopper, K. (2008). Absorption spectral slopes and slope ratios as indicators of molecular weight, source, and photobleaching of chromophoric dissolved organic matter, Limnology and Oceanography, 53(3), 955-969. https://doi.org/10.4319/lo.2008.53.3.0955
  36. Her, N., Amy, G., McKnight, D., Sohn, J., and Yoon, Y. (2003). Characterization of DOM as a function of MW by fluorescence EEM and HPLC-SEC using UVA, DOC, and fluorescence detection, Water Research, 37(17), 4295-4303. https://doi.org/10.1016/S0043-1354(03)00317-8
  37. Huguet, A., Vacher, L., Relexans, S., Saubusse, S., Froidefond, J. M., and Parlanti, E. (2009). Properties of fluorescent dissolved organic matter in the Gironde Estuary, Organic Geochemistry, 40(6), 706-719. https://doi.org/10.1016/j.orggeochem.2009.03.002
  38. Ishii, S. K. L. and Boyer, T. H. (2012). Behavior of reoccurring parafac components in fluorescent dissolved organic matter in natural and engineered systems: A critical review, Environmental Science and Technology, 46(4), 142-144. https://doi.org/10.1021/es2043504
  39. Jin, B., Lin, Z., Liu, W., Xiao, Y., Meng, Y., Yao, X., and Zhang, T. (2022). Spatiotemporal variations of dissolved organic matter in a typical multi-source watershed in northern China: A fluorescent evidence, Environmental Science and Pollution Research, 29(14), 20517-20529. https://doi.org/10.1007/s11356-021-17282-z
  40. Kalbitz, K., Solinger, S., Park, J. H., Michalzik, B., and Matzner, E. (2000). Controls on the dynamics dissolved organic matter in soils: A review, Soil Science, 165(4), 277-304. https://doi.org/10.1097/00010694-200004000-00001
  41. Kamjunke, N., von Tumpling, W., Hertkorn, N., Harir, M., Schmitt-Kopplin, P., Norf, H., Weitere, M., and Herzsprung, P. (2017). A new approach for evaluating transformations of dissolved organic matter (DOM) via high-resolution mass spectrometry and relating it to bacterial activity, Water Research, 123(15), 513-523. https://doi.org/10.1016/j.watres.2017.07.008
  42. Kim, T. H., Waska, H., Kwon, E., Suryaputra, I. G. N., and Kim, G. (2012). Production, degradation, and flux of dissolved organic matter in the subterranean estuary of a large tidal flat, Marine Chemistry, 1(10), 142-144. https://doi.org/10.1016/j.marchem.2012.08.002
  43. Lapierre, J. F. and Frenette, J. J. (2009). Effects of macrophytes and terrestrial inputs on fluorescent dissolved organic matter in a large river system, Aquatic Sciences, 71(1), 15-24. https://doi.org/10.1007/s00027-009-9133-2
  44. Lawrence, J. (1980). Semi-quantitative determination of fulvic acid, tannin and lignin in natural waters, Water Research, 14(4), 373-377. https://doi.org/10.1016/0043-1354(80)90085-8
  45. Lee, M. H., Lee, S. Y., Yoo, H. Y., Shin, K. H., and Hur, J. (2020). Comparing optical versus chromatographic descriptors of dissolved organic matter (DOM) for tracking the non-point sources in rural watersheds, Ecological Indicators, 117(5), 568-789. https://doi.org/10.1016/j.ecolind.2020.106682
  46. Li, D., Pan, B., Han, X., Li, J., Zhu, Q., and Li, M. (2021). Assessing the potential to use CDOM as an indicator of water quality for the sediment-laden Yellow river, China, Environmental Pollution, 289(3), 117970.
  47. Li, J., Zhao, L., Li, M., Min, Y., Zhan, F., Wang, Y., Sheng, L., and Bian, H. (2022). Changes in soil dissolved organic matter optical properties during peatland succession, Ecological Indicators, 143(4), 109-386. https://doi.org/10.1016/j.ecolind.2022.109386
  48. Li, P. and Hur, J. (2017). Utilization of UV-Vis spectroscopy and related data analyses for dissolved organic matter (DOM) studies, Critical Reviews in Environmental Science and Technology, 47(3), 131-154. https://doi.org/10.1080/10643389.2017.1309186
  49. Li, S., Lu, L., Wu, Y., Zhao, Z., Huang, C., Huang, T., Yang, H., Ma, X., and Jiang, Q. (2021). Investigation on depth-dependent properties and benthic effluxes of dissolved organic matter (DOM) in pore water from Plateau lake sediments, Ecological Indicators, 125(3), 107500.
  50. Li, Y., Xiao, K., Du, J., Han, B., Liu, Q., Niu, H., Ren, W., Tan, J., and Wang, Y. (2021). Spectroscopic fingerprints to track the fate of aquatic organic matter along an alpine headstream on the Tibetan Plateau, Science of the Total Environment, 792, 472-478. https://doi.org/10.1016/j.scitotenv.2021.148376
  51. Li, Y., Zhang, Y., Li, Z., Wan, J., Dang, C., and Fu, J. (2022). Characterization of colored dissolved organic matter in the northeastern South China Sea using EEMs-PARAFAC and absorption spectroscopy, Journal of Sea Research, 180, 102159.
  52. Lozovik, P. A., Morozov, A. K., Zobkov, M. B., Dukhovicheva, T. A., and Osipova, L. A. (2007). Allochthonous and autochthonous organic matter in surface waters in Karelia, Water Resources, 34(2), 702-808. https://doi.org/10.1134/S009780780702011X
  53. Weishaar, L. J., R. Aiken, G., A. Bergamaschi, B., S. Fram, M., Fujii, R., and Mopper, K. (2003). Evaluation of specific ultraviolet absorbance as an indicator of the chemical composition and eeactivity of dissolved oganic carbon, Environmental Science and Technology, 37(20), 4702-4708. https://doi.org/10.1021/es030360x
  54. Lyu, L., Liu, G., Shang, Y., Wen, Z., Hou, J., and Song, K. (2021). Characterization of dissolved organic matter (DOM) in an urbanized watershed using spectroscopic analysis, Chemosphere, 277, 130210.
  55. Ma, Y. and Li, S. (2020). Spatial and temporal comparisons of dissolved organic matter in river systems of the three Gorges reservoir region using fluorescence and UV-Visible spectroscopy, Environmental Research, 189(3), 46-138. https://doi.org/10.1016/j.envres.2020.109925
  56. McKnight, D. M., Boyer, E. W., Westerhoff, P. K., Doran, P. T., Kulbe, T., and Andersen, D. T. (2001). Spectrofluorometric characterization of dissolved organic matter for indication of precursor organic material and aromaticity, Limnology and Oceanography, 46(1), 38-48. https://doi.org/10.4319/lo.2001.46.1.0038
  57. Mcknight, D. M., Harnish, R., Wershaw, R. L., Baron, J. S., and Schiff, S. (1997). Chemical characteristics of particulate, colloidal, and dissolved organic material in Loch Vale watershed, Rocky mountain nationalpark, Biogeochemistry, 36(1), 30-78.
  58. Murphy, K. R., Bro, R., and Stedmon, C. A. (2014). Chemometric analysis of organic matter fluorescence, Aquatic organic matter fluorescence, Cambridge University Press, 339-375.
  59. Ohno, T. and Bro, R. (2006). Dissolved organic matter characterization using multiway spectral decomposition of fluorescence landscapes, Soil Science Society of America Journal, 70(6), 206-345. https://doi.org/10.2136/sssaj2006.0005
  60. Osburn, C. L., del Vecchio, R., and Boyd, T. J. (2014). Physicochemical effects on dissolved organic matter fluorescence in natural waters In aquatic organic matter fluorescence, Cambridge University Press, Cambridge, UK, 233-277.
  61. Parlanti, E., Worz, K., Geoffroy, L., and Lamotte, M. (2000). Dissolved organic matter fluorescence spectroscopy as a tool to estimate biological activity in a coastal zone submitted to anthropogenic inputs, Organic Geochemistry, 31(12), 124-178. https://doi.org/10.1016/S0146-6380(00)00124-8
  62. Peacock, M., Evans, C. D., Fenner, N., Freeman, C., Gough, R., Jones, T. G., and Lebron, I. (2014). UV-visible absorbance spectroscopy as a proxy for peatland dissolved organic carbon (DOC) quantity and quality: Considerations on wavelength and absorbance degradation, Environmental Sciences: Processes and Impacts, 16(6), 1793.
  63. Petrone, K. C., Fellman, J. B., Hood, E., Donn, M. J., and Grierson, P. F. (2011). The origin and function of dissolved organic matter in agro-urban coastal streams, Journal of Geophysical Research: Biogeosciences, 116(1), 682-811. https://doi.org/10.1029/2010JG001537
  64. Retelletti Brogi, S., Ha, S. Y., Kim, K., Derrien, M., Lee, Y. K., and Hur, J. (2018). Optical and molecular characterization of dissolved organic matter (DOM) in the Arctic ice core and the underlying seawater (Cambridge Bay, Canada): Implication for increased autochthonous DOM during ice melting, Science of The Total Environment, 627(4), 802-811. https://doi.org/10.1016/j.scitotenv.2018.01.251
  65. Shi, J., Jiang, G., Sun, Z., Guo, F., Wang, Q., and Liu, F. (2022). Dissolved organic matter tracers reveal contrasting characteristics in the concentrated flow zone and matrix-with-fractures zone of a sulfate-contaminated karst aquifer in South China, Applied Geochemistry, 146(3), 105-431. https://doi.org/10.1016/j.apgeochem.2022.105431
  66. Stanley, E. H., Powers, S. M., Lottig, N. R., Buffam, I., and Crawford, J. T. (2012). Contemporary changes in dissolved organic carbon (DOC) in human-dominated rivers: Is there a role for DOC management?, Freshwater Biology, 57(1), 2011-2613. https://doi.org/10.1111/j.1365-2427.2011.02613.x
  67. Stedmon, C. A. and Cory, R. M. (2008). Characterizing dissolved organic matter fluorescence with parallel factor analysis: A tutorial, Limnology and Oceanography: Methods, 6(11), 208-372. https://doi.org/10.4319/lom.2008.6.208
  68. Stedmon, C. A. and Cory, R. M. (2014). Biological origins and fate of fluorescent dissolved organic matter in aquatic environments. Aquatic organic matter fluorescence, Cambridge University Press, Cambridge, UK, 278-300.
  69. Stedmon, C. A. and Markager, S. (2005). Resolving the variability in dissolved organic matter fluorescence in a temperate estuary and its catchment using PARAFAC analysis, Limnology and Oceanography, 50(2), 208-372. https://doi.org/10.4319/lo.2005.50.2.0686
  70. Stedmon, C. A., Markager, S., and Bro, R. (2003). Tracing dissolved organic matter in aquatic environments using a new approach to fluorescence spectroscopy, Marine Chemistry, 82(5), 23-44. https://doi.org/10.1016/S0304-4203(03)00072-0
  71. Tanaka, K., Kuma, K., Hamasaki, K., and Yamashita, Y. (2014). Accumulation of humic-like fluorescent dissolved organic matter in the Japan Sea, Scientific Reports, 6(11), 208-372. https://doi.org/10.1038/srep05292
  72. Wang, X., Wu, Y., Jiang, Z., Ma, Q., Zhang, J., and Liu, S. (2017). Quantifying aquaculture-derived dissolved organic matter in the mesocosms of Sanggou bay using excitation-emission matrix spectra and parallel factor analysis, Journal of the World Aquaculture Society, 48(6), 909-926. https://doi.org/10.1111/jwas.12409
  73. Wilson, H. F. and Xenopoulos, M. A. (2008). Ecosystem and seasonal control of stream dissolved organic carbon along a gradient of land use, Ecosystems, 11(4), 142-144. https://doi.org/10.1007/s10021-008-9142-3
  74. Wu, J., Cheng, S., Cai, M. H., Wu, Y. P., Li, Y., Wu, J. C., Li, A. M., and Li, W. T. (2018). Applying UV absorbance and fluorescence indices to estimate inactivation of bacteria and formation of bromate during ozonation of water and wastewater effluent, Water Research, 145(1), 354-364. https://doi.org/10.1016/j.watres.2018.08.030
  75. Wu, Y. P., Ji, W. X., Liu, F., Wang, W. Q., Cai, M. H., Tian, Y. C., Zuo, Y. T., Shi, P., Li, Y., Li, W. T., and Li, A. M. (2022). Characterizing molecular weight distribution and optical properties of dissolved organic matter and unraveling the origins of anthropogenic fluorophores in Yangtze river and its tributaries, ACS EST Water, 2(6), 1056-1064. https://doi.org/10.1021/acsestwater.2c00028
  76. Zhang, Y., Shen, G., Hu, S., He, Y., Li, P., and Zhang, B. (2021). Deciphering of antibiotic resistance genes (ARGs) and potential abiotic indicators for the emergence of ARGs in an interconnected lake-river-reservoir system, Journal of Hazardous Materials, 410, 124-552. https://doi.org/10.1016/j.jhazmat.2020.124552
  77. Zhang, Y., Zhang, E., Yin, Y., van Dijk, M. A., Feng, L., Shi, Z., Liu, M., and Qin, B. (2010). Characteristics and sources of chromophoric dissolved organic matter in lakes of the Yungui Plateau, China, differing in trophic state and altitude, Limnology and Oceanography, 55(6), 142-144. https://doi.org/10.4319/lo.2010.55.6.2645
  78. Zhu, L., Zhao, Y., Bai, S., Zhou, H., Chen, X., and Wei, Z. (2020). New insights into the variation of dissolved organic matter components in different latitudinal lakes of northeast China, Limnology and Oceanography, 65(3), 113-165. https://doi.org/10.1002/lno.11316
  79. Zsolnay, A., Baigar, E., Jimenez, M., Steinweg, B., and Saccomandi, F. (1999). Differentiating with fluorescence spectroscopy the sources of dissolved organic matter in soils subjected to drying, Chemosphere, 38(1), 653-796. https://doi.org/10.1016/S0045-6535(98)00166-0