An improved method for fluorescence analysis of dissolved organic matter in cave drip water

AbstractDissolved organic matter (DOM) controls the degradation and sequestration of aquatic pollutants and, in turn, water quality. In particular, pollutant degradation is performed by oxidant species that are generated by exposure of DOM to solar light, yet, since DOM is a very complex mixture of poorly known substances, the relationships between potential oxidant precursors in DOM and their oxydative capacity is poorly known. Here, we hypothesized that production of oxidant species could be predicted using fluorescence analysis. We analysed water samples from an alluvial plain by fluorescence spectroscopy; the three-dimensional spectra were then decomposed into seven individual components using a multi-way algorithm. Components include a protein-like fluorophore, e.g. tryptophan-like and tyrosine-like, three humic fluorophores, 2-naphthoxyacetic acid, and a by-product. We compared component levels with the ability of water samples to generate reactive species under solar light. The results show a strong correlation between reactive species production and the intensity of two humic-like fluorophores assigned to reduced quinones. Monitoring these fluorophores should thus allow to predict the ability of DOM degradation of pollutants in surface waters.

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Oversimplification of Dissolved Organic Matter Fluorescence Analysis: Potential Pitfalls of Current Methods

Environmental Science & Technology ◽

10.1021/acs.est.6b06133 ◽

2016 ◽

Vol 51 (2) ◽

pp. 759-761 ◽

Cited By ~ 15

Author(s):

Fernando L. Rosario-Ortiz ◽

Julie A. Korak

Keyword(s):

Organic Matter ◽

Dissolved Organic Matter ◽

Fluorescence Analysis

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An analysis of dissolved organic matter from freshwater Karelian Lakes using reversed-phase high-performance liquid chromatography with online absorbance and fluorescence analysis

Moscow University Physics Bulletin ◽

10.3103/s002713491701009x ◽

2017 ◽

Vol 72 (1) ◽

pp. 68-75 ◽

Cited By ~ 7

Author(s):

D. A. Khundzhua ◽

S. V. Patsaeva ◽

O. A. Trubetskoj ◽

O. E. Trubetskaya

Keyword(s):

High Performance Liquid Chromatography ◽

Organic Matter ◽

Liquid Chromatography ◽

Dissolved Organic Matter ◽

High Performance ◽

Fluorescence Analysis ◽

Reversed Phase

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Quantification of lignin oxidation products as vegetation biomarkers in speleothems and cave drip water

Biogeosciences ◽

10.5194/bg-15-5831-2018 ◽

2018 ◽

Vol 15 (19) ◽

pp. 5831-5845 ◽

Cited By ~ 1

Author(s):

Inken Heidke ◽

Denis Scholz ◽

Thorsten Hoffmann

Keyword(s):

Organic Matter ◽

Sample Size ◽

Water Samples ◽

Solid Phase ◽

Oxidation Products ◽

Drip Water ◽

Cave Drip Water ◽

Lignin Oxidation ◽

The Individual ◽

Sensitive Method

Abstract. Here we present a sensitive method to analyze lignin oxidation products (LOPs) in speleothems and cave drip water to provide a new tool for paleo-vegetation reconstruction. Speleothems are valuable climate archives. However, compared to other terrestrial climate archives, such as lake sediments, speleothems contain very little organic matter. Therefore, very few studies on organic biomarkers in speleothems are available. Our new sensitive method allows us to use LOPs as vegetation biomarkers in speleothems. Our method consists of acid digestion of the speleothem sample followed by solid-phase extraction (SPE) of the organic matter. The extracted polymeric lignin is degraded in a microwave-assisted alkaline CuO oxidation step to yield monomeric LOPs. The LOPs are extracted via SPE and finally analyzed via ultrahigh-performance liquid chromatography (UHPLC) coupled to electrospray ionization (ESI) and high-resolution Orbitrap mass spectrometry (HRMS). The method was applied to stalagmite samples with a sample size of 3–5 g and cave drip water samples with a sample size of 100–200 mL from the Herbstlabyrinth-Advent Cave in Germany. In addition, fresh plant samples, soil water, and powdered lignin samples were analyzed for comparison. The concentration of the sum of eight LOPs (Σ8) was in the range of 20–84 ng g−1 for the stalagmite samples and 230–440 ng L−1 for the cave drip water samples. The limits of quantification for the individual LOPs ranged from 0.3–8.2 ng per sample or 1.5–41.0 ng mL−1 of the final sample solution. Our method represents a new and powerful analytical tool for paleo-vegetation studies and has great potential to identify the pathways of lignin incorporation into speleothems.

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