Characterization of high molecular weight dissolved organic compounds in natural waters by LC/ESI-MS

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:242353

Ross, A R; Orians, K J ^[1]; Ikonomou, M G ^[2]

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1. Univ. of British Columbia, Vancouver, British Columbia (Canada)
2. Dept. of Fisheries and Oceans, Sidney, British Columbia (Canada)

High molecular weight dissolved organic compounds such as peptides, polysaccharides and humic substances (humic and fulvic acids) play a major role in modifying the distribution and bioavailability of both organic and inorganic pollutants (e.g. pesticides and heavy metals) in natural waters. To predict the rate and extent of such processes, knowledge of the structure and physico-chemical properties of these species is required. Humic substances and their anthropogenic derivatives (e.g. chlorolignosulphonic acids) have proved difficult to characterize using conventional analytical techniques such as UV, NMR and FAB-MS. However, a combination of LC fractionation and electrospray ionization mass spectrometric (ESI-MS) analysis has the potential to provide the type of structural information required, including identification and location of functional groups. ESI is a soft ionization technique, and ESI-MS provides accurate molecular weight determinations for large polar and ionic substances with MW exceeding 100,000 Da. The authors have developed LC/MS based methodology to characterize high molecular weight (> 1,000 Da) dissolved organic compounds in aqueous samples. Following initial filtration and mild cleanup, samples were fractionated by high performance size-exclusion and reverse-phase chromatography. Mass analysis of the resolved components was carried out using a tandem mass spectrometer fitted with an ESI interface. The aim of the current methodology is to maintain natural conditions during analysis, thus preserving the integrity of both the parent compounds and derivatives formed by association with other solution components (e.g. trace metal complexes). Data demonstrating the abilities and limitations of this technique, its applicability to real samples and how it compares with existing analytical methods will be presented.

• OSTI ID: 242353
• Report Number(s): CONF-9511137--; ISBN 1-880611-03-1
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
BIOLOGICAL AVAILABILITY
CHEMICAL ANALYSIS
FORECASTING
INORGANIC COMPOUNDS
MASS SPECTROSCOPY
METALS
ORGANIC COMPOUNDS
STRUCTURE-ACTIVITY RELATIONSHIPS
WATER POLLUTION