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Example of Pirita River water HPLC-SEC-DAD chromatograms: a detection at 210, 254 and 280 nm, sample from January 10, 2014; b contour plot, sample from May 19, 2014; and c chromatogram of sample (b) at 210 nm with separated DOM fractions and respective absorbance spectra
Source publication
The change in the optical parameters of dissolved organic matter (DOM) from natural water samples of Pirita River in Estonia were studied during 2 years of winter–spring season. At present, the relative quantitative and qualitative composition of DOM components leached from soils to water, in relation to air and water temperatures and water level f...
Similar publications
Molecular size and dissolved organic carbon (DOC) distributions of dissolved organic matter (DOM) in seawater were determined qualitatively and quantitatively by high-performance size exclusion chromatography (HPSEC). To estimate the relationship between molecular size distribution and the DOC concentration of seawater DOM, seawater was desalinated...
Citations
... Chromatographic analysis procedure was described previously in [15,32]. Briefly, HPLC system with DAD (Agilent 1200 Series, Agilent Technologies, Stockport, UK) was used to obtain chromatograms and UV-Vis spectra of DOM. ...
... The HMM fraction (1-2% of total HPLC peak) was not present in all of the samples that were analysed (not detected in March samples, Nos. 1 and 2), and contained aggregated humic molecules. The HS fraction (broad peak eluting between 16 and 21 min) was clearly separated from the following PL fraction (sharp peak at 22 min, identified as tripeptide) [15]. The chromatograms of Figure 3b from sample No. 8 (6 May) show differences in the HS, PL, and LMM fractions. ...
... Large protein-like structures can be derived from bacteria and other biological activity. These HMM compounds are considered to be weakly bonded because of van der Waals forces and a change in hydrological conditions can possibly degrade the aggregates and produce LMM compounds of an aromatic character [15]. The HMM compounds can possibly be transformed by microbial action into bioavailable forms. ...
This study aims to investigate if high-resolution dissolved organic matter (DOM) data, obtained from water by chromatographic analyses, enable us to assess whether seasonal climate change and anthropogenic activities in the catchment area have an impact on the ecosystem’s sustainability. More specifically, the changes in the molecular properties of heterogeneous DOM from the hypertrophic River Vääna, Estonia, during the winter and spring seasons have been examined. The chromatographic HPLC method (HPLC-SEC), combined with UV-Vis spectroscopic detection, was used to characterize and fractionate DOM. Changes in several chromatographic/molecular parameters were investigated. The microbial-derived low-molecular-mass aromatic and heterocyclic compounds, humic substances (HS), and protein-like (PL) components were identified in the DOM. The HS to PL fractions ratio has been found to reflect the seasonal climatic change and can be applied as a potential environmental indicator. The River Vääna’s water was evaluated as sustainable, and even an anthropogenic impact was revealed. The results point out the usefulness of HPLC-SEC together with UV-Vis spectroscopy detection for climate change-related DOM studies in real environmental conditions.
... 3) The instrument has the advantages of simple structure, low maintenance cost and low repetition rate, and is suitable for on-line analysis (Attimarad 2012;Merás et al., 2002). However, due to the coexistence of multiple heavy metal ions in the same period in zinc smelting industrial wastewater, their chemical characteristics are similar, their mutual influence is serious (Rastogi et al., 2015), their absorption spectra overlap seriously (Lambert et al., 2017), and the full spectra information contains a lot of redundant non characteristic information (Fedenko et al., 2017), resulting in low accuracy and large prediction error of ultraviolet visible spectral analysis model (Lepane et al., 2015;Lee et al., 2017). Therefore, the traditional multivariate linear analysis method based on full band information modeling is difficult to accurately detect the concentration of polymetallic ions in zinc smelting wastewater (Rote and Bari, 2009;Khan et al., 2020). ...
Aiming at the problems of low accuracy and large prediction errors caused by the serious overlap of multi-metal spectral signals in zinc smelting industrial wastewater, a characteristic interval modeling method is proposed. First, according to the absorption spectra of mixed solution, the characteristic intervals of copper and nickel are preliminarily screened by using different partition lengths. Second, take the smallest root mean squares error of cross validation and the largest correlation coefficient as the evaluation indicators, compare the full-spectral model and each local model, and select the optimal feature sub-intervals of copper and nickel. Last, the partial least squares method is used to model the combined wavelengths of the optimal sub-intervals to realize the simultaneous detection of copper and nickel. The linear determination ranges are 0.3–3.0 mg/L for copper and nickel. the correlation coefficients of copper and nickel are 0.9974 and 0.9966, respectively. The results show that the method reduces the complexity of the wavelength variable screening process, improves the accuracy of the model, and lays the foundation for the accurate analysis of polymetallic ions in zinc smelting industrial wastewater.
... In the present day the understanding of freshwater biota and its vulnerability due to climate changes has improved [1]. Climate change is expected to modify the physical characteristics of aquatic environments and intensify organic matter and energy fluxes in lakes and in their catchment area [2], [3]. This also highlights the already well-known problem of freshwaters in the World and in Europe -eutrophication, which can lead to increased productivity of water ecosystems. ...
Lake ecosystems are important elements of hydrological regime, the quality of these ecosystems is affected by anthropogenic actions, and therefore, a variety of organisms, living in these habitats depend on the applied management solutions. Due to human activities freshwater ecosystems suffer from loss of biodiversity and increased eutrophication. Therefore, important aspects related to lake management include knowledge about the water quality, ecosystem response to climate change as well as increased risks of appearance and spreading of invasive species. Water quality, content of oxygen, nutrients, phytoplankton and distribution of macrophytes, including invasive species were analysed in Balvu and Pērkonu lakes. Presence of invasive species Canadian waterweed ( Elodea canadensis ) was detected, however, common reed ( Phragmites australis ) can be considered as expansive species. The analysis of current situation and existing management measures indicates persistent spreading of those species. Significant changes of lake water quality and climate may increase possible spreading of other, more aggressive, invasive species, for example – Nuttall’s waterweed ( Elodea nuttallii ).
... In recent years, the commonly used methods for on-line detection of metal ions include potentiometric titration (Attimarad 2012), polarography (Duran Meras et al., 2002), inductively coupled plasma mass spectrometry (Rastogi et al., 2015), ultraviolet visible spectroscopy (Lambert et al., 2017) and laser-induced breakdown spectroscopy (Fedenko et al., 2017). As a conventional quantitative analysis method, ultraviolet visible spectroscopy is widely used in the field of analysis and detection due to its advantages of simplicity, accuracy, rapidity, multifunction and low cost (Lepane et al., 2015;Lee and Oh, 2017). However, in the zinc hydrometallurgical purification process, when using ultraviolet-visible spectroscopy to detect nickel (Ni) in zinc sulfate solution, there are the following difficulties (Rote and Bari, 2009;Khan et al., 2020): 1) in zinc sulfate solution, the concentration ratio of main zinc to nickel ion is as high as 10 5 , which makes the nickel spectral signal seriously masked by the main zinc signal; 2) the chemical characteristics of zinc and nickel in zinc solution are similar, and the spectral characteristic information area is concentrated and the effective band is narrow, which makes their spectral signal seriously overlap and interfere with each other; 3) due to the increase of particle density in zinc sulfate solution, the absorptivity and transmissivity of the solution to the incident light are changed, resulting in the spectral characteristics of nickel in the solution seriously deviate from Beer-Lambert law, which makes it difficult to quantitatively analyze and detect nickel; 4) due to the fluctuation of the main zinc, the random noise of the testing instrument and the weak background interference of reagents such as chromogenic agents, these factors will affect the detection accuracy of nickel ion. ...
In the zinc hydrometallurgical purification process, the concentration ratio of zinc ion to trace nickel ion is as high as 10⁵, so that the nickel spectral signal is completely covered by high concentration zinc signal, resulting in low sensitivity and nonlinear characteristics of nickel spectral signal. Aiming at the problem that it is difficult to detect nickel in zinc sulfate solution, this paper proposes a nonlinear integrated modeling method of extended Kalman filter based on Adaboost algorithm. First, a non-linear nickel model is established based on nickel standard solution. Second, an extended Kalman filter wavelength optimization method based on correlation coefficient is proposed to select wavelength variables with high signal sensitivity, large amount of information and strong nonlinear correlation. Finally, a nonlinear integrated modeling method based on Adaboost algorithm is proposed, which uses extended Kalman filter as a basic submodel, and realizes the stable detection of trace nickel through the weighted combination of multiple basic models. The results show that the average relative error of this method for detecting nickel is 4.56%, which achieves accurate detection of trace nickel in zinc sulfate solution.
... Carrillo-Gonzalez, Gonzalez-Chavez, Aitkenhead-Peterson, Hons, & Loeppert, 2013;Lepane, Depret, Väli, & Suursööt, 2015). The isolation and determination of soil FOC were conducted using 1.8 g cm −3 NaI solution according to the procedure described by Elliott and Cambardella (1991). ...
The microbial community and soil organic carbon (SOC), which play vital roles in soil fertility and the global C cycle, have been heavily altered due to land‐use changes and long‐term fertilization. However, the effect of long‐term fertilization on the microbial community and SOC in land‐use changed soil is still unclear. In this study, a 26‐year field experiment is conducted to detect the bacterial community and SOC stocks in the soils from meadow grasslands (M), croplands without fertilization (NF), and croplands with fertilization for 13 (F13a) and 26 years (F26a) in the Tibetan plateau. The results show that land‐use change from meadow grassland to cropland induced a decrease in the SOC stocks of total (TOC), free (FOC) and permanganate‐oxidizable OC (POxC) by 61.8%–85.0%, 51.1%–82.8% and 78.4%–95.8%, respectively. Long‐term fertilization increased the SOC stocks by 124.4%–419.0%, which was still lower than those in the M soils. In addition, macroaggregates (MAA) and bacterial diversity displayed reductions when the land‐use was changed from grassland to cropland, but they were enhanced after long‐term fertilization. Land‐use change and long‐term fertilization both altered the microbial community. MAA served as habitat for the microbial community and physical protection for SOC. This may be a key driver of changes in the bacterial community and SOC. This study demonstrates that long‐term fertilization alters the microbial community but fails to restore SOC stocks to the level of uncropped meadow soils. Long‐term fertilization integrated with macroaggregates are required to improve OC sequestration for developping sustainable agriculture and mitigating global climate change.
... A higher proportion of peptide-like substances in the cropped cinnamon soils and a higher proportion of tryptophan-like substances in the cropped red soils were also found in comparison with the corresponding natural soils. This may be due to a lower input and a faster decomposition of the SOM in the cropped soils [53,54]. The removal of above-ground biomass of crops by harvesting reduced the input of plant residues, and therefore, DOM in the cropped soil relied more on allochthonous sources [16]. ...
Background
Exploration of composition and chemical characteristics of soil dissolved organic matter (DOM) is significant to understand its biogeochemical role in terrestrial ecosystems. A total of 43 cropped and 16 natural soils (0–20 cm) under four soil types (cinnamon, chernozem, red and paddy soils) across China were collected to investigate the spectral characteristics of DOM using UV–Vis and 3D-EEM spectroscopy.
Results
The chernozem soils exhibited the highest aromaticity and humification degree among the four soil types. Ranges of biological index (BIX, 0.53–1.17) and fluorescence index (FI, 1.55–2.10) were found in the investigated DOM, showing joint contribution from allochthonous and autochthonous sources. Higher BIX and FI in the DOM of the paddy and red soils indicated a greater reliance on autochthonous sources for these two soil types. The cropped soils showed no significant differences in chemical characteristics and sources from the natural soils for the cinnamon, chernozem and red soils. UVA (16.2–47.9%) and UVC fulvic-like substances (15.4–40.5%) were the prevailing DOM components, which were highest in the chernozem soils. Additionally, the cropped soils had a higher proportion of humic-like substances than the natural soils in the DOM.
Conclusions
Both soil type and land-use strongly affected the chemical characteristics of soil DOM, but only soil type had an impact on the DOM composition for the collected soils. These findings may contribute to the prediction of the biochemical behavior of soil DOM under different soil types and land-uses in terrestrial ecosystems.
... Moreover, it is known that humic structures can incorporate protein-like fractions in the result of weak interactions based on π-π and/or van der Waals forces between the DOM components. 36,37 Recent studies indicate that not only proteins but also humic supramolecules containing certain structures (derived from phenol or aniline) can contribute to protein-like fluorescence. 38 "Red-shifted" humic/fulvic-like fluorescence at 370/500 nm (emission at longer wavelengths) can be related to highly conjugated aromatic compounds of high MW, whereas "blue-shifted" humic/fulvic-like fluorescence at 330/425 nm (emission at shorter wavelengths) can be assigned to compounds with lower aromaticity and lower MWs. ...
This paper provides a glimpse into removal of dissolved organic matter (DOM) during conventional drinking water treatment and evaluates the potential of high-performance size-exclusion chromatography (HPSEC) as a supplementary routine...
Humic ligands from boreal rivers have been identified as important sources of iron-binding ligands to the coastal marine environment but remain poorly characterized. A novel method using Fourier transformed infrared spectroscopy (FTIR) was used to identify and quantify iron-binding ligands present in a boreal river in Newfoundland, Canada. 20 to 35% of the total iron load was carried through an artificial salinity gradient, and remained in solution at 35 salinity. Using FTIR combined with linear regression and 2D correlation analysis, we identified two pools of organic ligands, with different behaviour with regards to iron across the salinity gradient. The weaker ligand pool consisted of alkenes, ethers, and esters, and was found to release iron to flocculation at low salinities, and not contribute to iron transport into the marine environment. The stronger ligand group contained carboxylic acids and aliphatic functional groups. This group appears to contain two subgroups, one which was able to retain iron in the dissolved phase at 35 salinity, and another that flocculated out with iron across the salinity gradient. The strong ligands that retain iron in solution through the salinity gradient provide a much-needed source of the micronutrient to the coastal and marine environment, while the other subgroup sequesters iron and carbon in estuarine sediments. The balance between these two subgroups appears to be controlled by the hydrographic and weather conditions at the time of sampling, suggesting a dynamic ligand-iron relationship throughout the year, impacting the biogeochemical cycles of both iron and carbon in contrasting ways.
