scholarly journals Spectral characteristics of water-soluble and alkaline-soluble humic substances of fallow soils

2019 ◽  
Author(s):  
K. Giniyatullin ◽  
E. Smirnova ◽  
R. Okunev
Keyword(s):  
Humic Substances ◽  
Spectral Characteristics ◽  
Water Soluble

scholarly journals MODIFICATION OF HUMIC SUBSTANCES FOR DEVELOPMENT OF MATERIALS FOR ENVIRONMENTAL TECHNOLOGIES

2019 ◽  
Vol 1 ◽  
pp. 101
Author(s):  
Maris Klavins
Keyword(s):  
Molecular Weight ◽  
Metal Ions ◽  
Humic Substances ◽  
Functional Groups ◽  
Metal Ion ◽  
Spectral Characteristics ◽  
Water Soluble ◽  
13C Nuclear Magnetic Resonance ◽  
Mobility Behaviour ◽  
Derivatives Of

Humic substances are high molecular weight refractory polycationites formed during decay of living organic matter and through biosynthesis of low molecular weight organic substances (metabolites or decay products of living organisms). Presence of many functional groups in the structure of humic substances determines their ability to interact with metal ions forming stable complexes and influencing metal ion speciation in the environment and mobility, behaviour and speciation forms in the environment. Presently humic substances are a product of industrial scale and quantities in amounts of hundreds of tons are produced. The aim of this study is to analyse derivatization possibilities of humic substances. To achieve this aim derivatization of humic substances using acylation (at first introduction of acetylgroups, but also changing length acyl chains are considered) are used. Also alkylation is used. Mild oxidation can help to obtain modified products with reduced molecular weight. Another approach includes introduction of new functional groups and structures. To achieve this aim, conjugates with short peptides, amines and sugar derivatives using coupling with water-soluble carbodiimides are obtained. As basic characteristics elemental analysis as well as functional analysis have been used, supported with Fourier transform infrared (FTIR), 13C nuclear magnetic resonance spectrometry and other methods. Derivatives of humic substances containing sulpho, amino, and hydroxylgroups and thiolgroups were synthesized and their properties were analyzed in respect to their their elemental composition; functional group content changes in spectral characteristics. The derivatives of humic substances showed significant differences in the number and in ability to interact with the metal ions, which were reflected in their complexation properties towards metal ions. FTIR spectra gave evidence of the presence of metal ions, strongly bound and protected in inner sphere complexes. The obtained derivatives of humic substances can be used for remediation of environment contaminated with heavy metal ions.

scholarly journals Mass spectral characterization of primary emissions and implications in source apportionment of organic aerosol

2020 ◽  
Vol 13 (6) ◽  
pp. 3205-3219 ◽  
Author(s):  
Weiqi Xu ◽  
Yao He ◽  
Yanmei Qiu ◽  
Chun Chen ◽  
Conghui Xie ◽  
...  
Keyword(s):  
Source Apportionment ◽  
Spectral Characteristics ◽  
Organic Aerosol ◽  
Water Soluble ◽  
Spectral Characterization ◽  
Rural Site ◽  
Spectral Features ◽  
Mass Spectral ◽  
Spectral Profiles ◽  
Primary Emissions

Abstract. Source apportionment of organic aerosol (OA) from aerosol mass spectrometer (AMS) or aerosol chemical speciation monitor (ACSM) measurements relies largely upon mass spectral profiles from different source emissions. However, the changes in mass spectra of primary emissions from AMS–ACSM with the newly developed capture vaporizer (CV) are poorly understood. Here we conducted 21 cooking, crop straw, wood, and coal burning experiments to characterize the mass spectral features of OA and water-soluble OA (WSOA) using SV-AMS and CV-ACSM. Our results show overall similar spectral characteristics between SV-AMS and CV-ACSM for different primary emissions despite additional thermal decomposition in CV, and the previous spectral features for diagnostics of primary OA factors are generally well retained. However, the mass spectral differences between OA and WSOA can be substantial for both SV-AMS and CV-ACSM. The changes in f55 (fraction of m∕z 55 in OA) vs. f57, f44 vs. f60, and f44 vs. f43 in CV-ACSM are also observed, yet the evolving trends are similar to those of SV-AMS. By applying the source spectral profiles to a winter CV-ACSM study at a highly polluted rural site in the North China Plain, the source apportionment of primary OA was much improved, highlighting the two most important primary sources of biomass burning and coal combustion (32 % and 21 %). Considering the rapidly increasing deployments of CV-ACSM and WSOA studies worldwide, the mass spectral characterization has significant implications by providing essential constraints for more accurate source apportionment and making better strategies for air pollution control in regions with diverse primary emissions.

Phosphorescent porphyrin probes in biosensors and sensitive bioassays

2000 ◽  
Vol 28 (2) ◽  
pp. 74-77 ◽  
Author(s):  
D. B. Papkovsky ◽  
T. O'Riordan ◽  
A. Soini
Keyword(s):  
Oxygen Sensor ◽  
Spectral Characteristics ◽  
Screening Method ◽  
High Sensitivity ◽  
Water Soluble ◽  
Fluorescent Detection ◽  
Rapid Screening ◽  
Time Resolved ◽  
Phosphorescence Lifetime ◽  
Practical Applications

Platinum(II) and palladium(II) complexes of porphyrins and related tetrapyrrolic pigments emit strong phosphorescence at room temperatures, which is characterized by long lifetimes falling into the sub-millisecond range and long-wave spectral characteristics. These features make the dyes useful as probes for a number of bioanalytical applications, particularly those employing time-resolved fluorescent detection. They can provide high sensitivity and selectivity, together with rather simple instrumental set-up. A number of analytical systems are now under development that are based on the use of phosphorescent porphyrin probes. Experimental results are presented on the following systems: (i) fibre-optic phosphorescence lifetime-based oxygen sensor on the basis of hydrophobic platinum-porphyrins and development of advanced sensing materials and prototype instrumentation; (ii) practical applications of the optical oxygen sensor, including a sensitive immunosensor that employs glucose oxidase labels, a rapid screening method for cell viability in microtitre-plate format, non-destructive measurement of oxygen in packaged foods and reagentless biosensors for metabolites (glucose, lactate); and (iii) the use of water-soluble platinum- and palladium-porphyrins as labels for ultra-sensitive time-resolved phosphorescence immunoassays.

On-the-Fly Fluorescence Lifetime Detection of Humic Substances in Capillary Electrophoresis

2003 ◽  
Vol 57 (3) ◽  
pp. 256-265 ◽  
Author(s):  
Joseph D. Hewitt ◽  
Linda B. McGown
Keyword(s):  
Humic Substances ◽  
Fluorescence Lifetime ◽  
Spectral Characteristics ◽  
Emission Spectra ◽  
Fulvic Acids ◽  
Fluorescence Decay ◽  
Fluorescence Excitation ◽  
Lifetime Analysis ◽  
Decay Profile ◽  
Fluorescence Lifetime Detection

On-the-fly fluorescence lifetime detection was investigated as a tool for studying humic substances in capillary zone electrophoresis (CZE). Humic substances are complex, heterogeneous mixtures of natural products that tend to migrate in a single, broad CZE peak. The intrinsic fluorescence lifetime of five humic substances from the International Humic Substances Society (IHSS) was monitored using excitation at 488 or 364 nm to produce intensity-lifetime electropherograms for each of the substances. Each frequency-domain lifetime measurement, collected at sub-second intervals during the CZE run, contains the equivalent of a complete decay profile. Lifetime analysis of each decay profile was used to construct a lifetime-resolved electropherogram for each lifetime component, from which the variation in relative intensity contributions of each lifetime across the broad CZE peak could be determined. Absorption spectra, fluorescence excitation–emission spectra, and lifetime profiles of batch solutions of the samples were determined as well. It was found that, whereas absorption and fluorescence spectral characteristics tended to discriminate between humic acids and fulvic acids, the batch solution lifetime profiles discriminated instead between samples from different sources, regardless of fraction. On-the-fly lifetime detection provided a more detailed view of the fluorescence decay of the samples, including greater resolution of lifetimes for two of the fulvic acids and greater discrimination among samples based on lifetime profiles across the CZE peaks.

scholarly journals The Structure of Humic Substances in the Agricultural Genetically Modified Soils of the Kansk Forest-Steppe

2019 ◽  
Vol 8 (4) ◽  
pp. 9613-9616
Keyword(s):  
Organic Matter ◽  
Spatial Variability ◽  
Humic Substances ◽  
Soil Cover ◽  
Water Soluble ◽  
Total Carbon ◽  
Soil Conditions ◽  
Forest Steppe ◽  
Soluble Organic Matter ◽  
False Flax

In two long-arable areas that were intended for sowing rapeseed and false flax for oilseeds at LLC «Experimental Industrial Farm Solyanskoye» in the Kansk forest-steppe, the structure and humus substances reserves in agrochernozems were studied. The soil cover of key plot No. 1 with the wide-steeply-sloping terrain with weakly pronounced microrelief, which was intended for rape, was dominated by typical medium and strong clayey-illuvial agrochernozems. Key plot No. 2 intended for false flax was located on a smooth hillside of a wide ridge and was characterized by the complexity of the soil cover represented by a combination of clay-illuvial typical agrochernozems of various kinds, thick podzolized clay-illuvial agrochernozems, and thin cryogenic micellar agrochernozems. It has been shown that agrochernozems featured high content of humus in the layer both 0 – 20 and 0 – 40 cm thick. The content of humus carbon (Ctot) and that of carbon of the water-soluble organic matter (CH2O) had little spatial variability (CV = 1.3 – 11.7 %), unlike the carbon content of the alkali-soluble organic matter (C 0.1 n. NaOH), which in the studied agrochernozems had a very high degree of spatial variability (Cv = 18.7 – 66.1 %). Heterogeneity of the soil cover of the slope part of the plot was the factor that determined the average reduction in the content of the reserves of all fractions of humic substances, except for the water-soluble humus carbon. It has been found that the share of the reserves of stable humus carbon (Cstab) was 89 – 95 % of the total carbon reserves of humus, thus the share of CH2O and C0.1 n. NaOH decreased with increasing the complexity of the soil cover from 11 to 5 % of Ctotal. Fields with a pronounced meso- and microrelief and thin kinds of agrochernozems are recommended for sowing false flax, which is a crop that is less demanding to the soil conditions than rapeseed.

Influence de l'application de superphosphate et de K2SO4•MgSO4 avec l'urée à un humus de forêt de pin gris. II. Dissolution des matières humiques et rétention ionique

1976 ◽  
Vol 6 (3) ◽  
pp. 293-298
Author(s):  
D. Carrier ◽  
B. Bernier
Keyword(s):  
Humic Substances ◽  
Magnesium Sulphate ◽  
Jack Pine ◽  
Water Soluble ◽  
Water Extraction ◽  
Incubation Experiment ◽  
Triple Superphosphate ◽  
Humus Layer ◽  
Potassium Magnesium

In an incubation experiment, the application of urea (224 kg N/ha) to jack pine (Pinusbanksiana Lamb.) raw humus resulted in significant amounts of water-soluble humic substances. When triple superphosphate (TSP: 48–192 kg P/ha) or potassium–magnesium sulphate (SPM: 198 kg K/ha) were applied with urea, the solubilization of humic substances was appreciably reduced. The retention of applied cations, particularly Ca and Mg, against water extraction from the humus was strongly enhanced when urea was applied with TSP and (or) SPM; TSP-phosphorous retention in the humus layer was also increased.

Extraction of extracellular polymeric substances (EPS) from biofilms using a cation exchange resin

1995 ◽  
Vol 32 (8) ◽  
pp. 157-164 ◽  
Author(s):  
A. Jahn ◽  
P. H. Nielsen
Keyword(s):  
Cation Exchange ◽  
Humic Substances ◽  
Batch Culture ◽  
Extraction Method ◽  
Extracellular Polymeric Substances ◽  
Exchange Resin ◽  
Cation Exchange Resin ◽  
Water Soluble ◽  
Extraction Time ◽  
Plate Count

A cation exchange resin was used to extract water soluble EPS material from different sewer biofilms and a biofilm monoculture of P.putida. The extraction method seemed to be especially suitable for extracting humic substances and proteins from biofilms but also carbohydrate could be extracted, depending on the nature of the sample. Extraction conditions must be well defined because the extraction efficiency was dependent on stirring intensity, amount of cation exchange resin and extraction time. Up to 20% of the total biofilm protein was found in the DOWEX-extractable fraction. No significant cell-lysis up to 2 hours of extraction time could be detected by acridine orange (AO) direct counts. The same was true when applying the extraction method to a batch culture of P.putida. However, the number of viable cells in the batch culture as recorded by plate count technique was reduced to 28 % after 30 min of extraction. In conclusion, proteins and humic substances can be extracted from biofilm EPS in considerable amounts and should be investigated more in detail when analysing the properties of the EPS matrix of a biofilm.

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