Spectrofluorometric characterization of dissolved organic matter for indication of precursor organic material and aromaticity

D. M. McKnight, E. W. Boyer, Paul Westerhoff, P. T. Doran, T. Kulbe, D. T. Andersen

Research output: Contribution to journalArticle

1462 Citations (Scopus)

Abstract

We studied the fluorescence properties of fulvic acids isolated from streams and rivers receiving predominantly terrestrial sources of organic material and from lakes with microbial sources of organic material. Microbially derived fulvic acids have fluorophores with a more sharply defined emission peak occurring at lower wavelengths than fluorophores in terrestrially derived fulvic acids. We show that the ratio of the emission intensity at a wavelength of 450 nm to that at 500 nm, obtained with an excitation of 370 nm, can serve as a simple index to distinguish sources of isolated aquatic fulvic acids. In our study, this index has a value of ∼1.9 for microbially derived fulvic acids and a value of∼1.4 for terrestrially derived fulvic acids. Fulvic acids isolated from four large rivers in the United States have fluorescence index values of 1.4-1.5, consistent with predominantly terrestrial sources. For fulvic acid samples isolated from a river, lakes, and groundwaters in a forested watershed, the fluorescence index varied in a manner suggesting different sources for the seepage and streamfed lakes. Furthermore, we identified these distinctive fluorophores in filtered whole water samples from lakes in a desert oasis in Antarctica and in filtered whole water samples collected during snowmelt from a Rocky Mountain stream. The fluorescence index measurement in filtered whole water samples in field studies may augment the interpretation of dissolved organic carbon sources for understanding carbon cycling in aquatic ecosystems.

Original languageEnglish (US)
Pages (from-to)38-48
Number of pages11
JournalLimnology and Oceanography
Volume46
Issue number1
StatePublished - 2001

Fingerprint

fulvic acids
dissolved organic matter
fulvic acid
Lakes
fluorescent dyes
fluorescence
Fluorescence
Rivers
lakes
lake
rivers
wavelengths
Water
Carbon
river
wavelength
sampling
emissions factor
forested watersheds
mountain stream

ASJC Scopus subject areas

  • Medicine(all)
  • Aquatic Science

Cite this

Spectrofluorometric characterization of dissolved organic matter for indication of precursor organic material and aromaticity. / McKnight, D. M.; Boyer, E. W.; Westerhoff, Paul; Doran, P. T.; Kulbe, T.; Andersen, D. T.

In: Limnology and Oceanography, Vol. 46, No. 1, 2001, p. 38-48.

Research output: Contribution to journalArticle

McKnight, D. M. ; Boyer, E. W. ; Westerhoff, Paul ; Doran, P. T. ; Kulbe, T. ; Andersen, D. T. / Spectrofluorometric characterization of dissolved organic matter for indication of precursor organic material and aromaticity. In: Limnology and Oceanography. 2001 ; Vol. 46, No. 1. pp. 38-48.
@article{d5e9544870b14812bdf640254cfe6724,
title = "Spectrofluorometric characterization of dissolved organic matter for indication of precursor organic material and aromaticity",
abstract = "We studied the fluorescence properties of fulvic acids isolated from streams and rivers receiving predominantly terrestrial sources of organic material and from lakes with microbial sources of organic material. Microbially derived fulvic acids have fluorophores with a more sharply defined emission peak occurring at lower wavelengths than fluorophores in terrestrially derived fulvic acids. We show that the ratio of the emission intensity at a wavelength of 450 nm to that at 500 nm, obtained with an excitation of 370 nm, can serve as a simple index to distinguish sources of isolated aquatic fulvic acids. In our study, this index has a value of ∼1.9 for microbially derived fulvic acids and a value of∼1.4 for terrestrially derived fulvic acids. Fulvic acids isolated from four large rivers in the United States have fluorescence index values of 1.4-1.5, consistent with predominantly terrestrial sources. For fulvic acid samples isolated from a river, lakes, and groundwaters in a forested watershed, the fluorescence index varied in a manner suggesting different sources for the seepage and streamfed lakes. Furthermore, we identified these distinctive fluorophores in filtered whole water samples from lakes in a desert oasis in Antarctica and in filtered whole water samples collected during snowmelt from a Rocky Mountain stream. The fluorescence index measurement in filtered whole water samples in field studies may augment the interpretation of dissolved organic carbon sources for understanding carbon cycling in aquatic ecosystems.",
author = "McKnight, {D. M.} and Boyer, {E. W.} and Paul Westerhoff and Doran, {P. T.} and T. Kulbe and Andersen, {D. T.}",
year = "2001",
language = "English (US)",
volume = "46",
pages = "38--48",
journal = "Limnology and Oceanography",
issn = "0024-3590",
publisher = "American Society of Limnology and Oceanography Inc.",
number = "1",

}

TY - JOUR

T1 - Spectrofluorometric characterization of dissolved organic matter for indication of precursor organic material and aromaticity

AU - McKnight, D. M.

AU - Boyer, E. W.

AU - Westerhoff, Paul

AU - Doran, P. T.

AU - Kulbe, T.

AU - Andersen, D. T.

PY - 2001

Y1 - 2001

N2 - We studied the fluorescence properties of fulvic acids isolated from streams and rivers receiving predominantly terrestrial sources of organic material and from lakes with microbial sources of organic material. Microbially derived fulvic acids have fluorophores with a more sharply defined emission peak occurring at lower wavelengths than fluorophores in terrestrially derived fulvic acids. We show that the ratio of the emission intensity at a wavelength of 450 nm to that at 500 nm, obtained with an excitation of 370 nm, can serve as a simple index to distinguish sources of isolated aquatic fulvic acids. In our study, this index has a value of ∼1.9 for microbially derived fulvic acids and a value of∼1.4 for terrestrially derived fulvic acids. Fulvic acids isolated from four large rivers in the United States have fluorescence index values of 1.4-1.5, consistent with predominantly terrestrial sources. For fulvic acid samples isolated from a river, lakes, and groundwaters in a forested watershed, the fluorescence index varied in a manner suggesting different sources for the seepage and streamfed lakes. Furthermore, we identified these distinctive fluorophores in filtered whole water samples from lakes in a desert oasis in Antarctica and in filtered whole water samples collected during snowmelt from a Rocky Mountain stream. The fluorescence index measurement in filtered whole water samples in field studies may augment the interpretation of dissolved organic carbon sources for understanding carbon cycling in aquatic ecosystems.

AB - We studied the fluorescence properties of fulvic acids isolated from streams and rivers receiving predominantly terrestrial sources of organic material and from lakes with microbial sources of organic material. Microbially derived fulvic acids have fluorophores with a more sharply defined emission peak occurring at lower wavelengths than fluorophores in terrestrially derived fulvic acids. We show that the ratio of the emission intensity at a wavelength of 450 nm to that at 500 nm, obtained with an excitation of 370 nm, can serve as a simple index to distinguish sources of isolated aquatic fulvic acids. In our study, this index has a value of ∼1.9 for microbially derived fulvic acids and a value of∼1.4 for terrestrially derived fulvic acids. Fulvic acids isolated from four large rivers in the United States have fluorescence index values of 1.4-1.5, consistent with predominantly terrestrial sources. For fulvic acid samples isolated from a river, lakes, and groundwaters in a forested watershed, the fluorescence index varied in a manner suggesting different sources for the seepage and streamfed lakes. Furthermore, we identified these distinctive fluorophores in filtered whole water samples from lakes in a desert oasis in Antarctica and in filtered whole water samples collected during snowmelt from a Rocky Mountain stream. The fluorescence index measurement in filtered whole water samples in field studies may augment the interpretation of dissolved organic carbon sources for understanding carbon cycling in aquatic ecosystems.

UR - http://www.scopus.com/inward/record.url?scp=0035135071&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0035135071&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0035135071

VL - 46

SP - 38

EP - 48

JO - Limnology and Oceanography

JF - Limnology and Oceanography

SN - 0024-3590

IS - 1

ER -