scholarly journals Spectroscopic Characteristics of Dissolved Organic Matter in Afforestation Forest Soil of Miyun District, Beijing

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Shi-Jie Gao ◽  
Chen Zhao ◽  
Zong-Hai Shi ◽  
Jun Zhong ◽  
Jian-Guo Liu ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Microbial Biomass Carbon ◽  
Soil Samples ◽  
Hydroxyl Groups ◽  
H Nmr ◽  
Spectroscopic Characteristics ◽  
Aromatic Components ◽  
A Minor ◽  
Aliphatic Chains

In this study, soil samples collected from different plain afforestation time (1 year, 4 years, 10 years, 15 years, and 20 years) in Miyun were characterized, including total organic carbon (TOC), total nitrogen (TN), total phosphorus (TP), available K (K+), microbial biomass carbon (MBC), and dissolved organic carbon (DOC). The DOM in the soil samples with different afforestation time was further characterized via DOC, UV-Visible spectroscopy, excitation-emission matrix (EEM) fluorescence spectroscopy, and1H NMR spectroscopy. The results suggested that the texture of soil sample was sandy. The extracted DOM from soil consisted mainly of aliphatic chains and only a minor aromatic component. It can be included that afforestation can improve the soil quality to some extent, which can be partly reflected from the indexes like TOC, TN, TP, K+, MBC, and DOC. And the characterization of DOM implied that UV humic-like substances were the major fluorophores components in the DOM of the soil samples, which consisted of aliphatic chains and aromatic components with carbonyl, carboxyl, and hydroxyl groups.

Synthesis and Characterization of an Alendronate-Chitosan Conjugate

2011 ◽  
Vol 140 ◽  
pp. 53-57 ◽  
Author(s):  
Xiao Hong Shao ◽  
Ji Qing Xu ◽  
Yan Peng Jiao ◽  
Chang Ren Zhou
Keyword(s):  
Drug Delivery ◽  
Drug Delivery System ◽  
Synthesis And Characterization ◽  
Hydroxyl Groups ◽  
Amino Groups ◽  
H Nmr ◽  
Ft Ir ◽  
Novel Drug Delivery System ◽  
Novel Drug

The biomineral-binding alendronate-chitosan conjugate (Scheme 1) was developed as a novel drug delivery system. Alendronate was conjugated to the hydroxyl groups of chitosan, thereby maintaining the amino groups of chitosan intact. By means of FT-IR and 1H NMR, the characterization was conducted to confirm the successful synthesis of alendronate-chitosan conjugate.

scholarly journals Influence of organic and mineral fertilisation on organic matter fractions of a Brazilian Acrisol under maize/common bean intercrop

Soil Research ◽  
2007 ◽  
Vol 45 (1) ◽  
pp. 25 ◽  
Author(s):  
L. F. C. Leite ◽  
E. S. Mendonça ◽  
P. L. O. A. Machado
Keyword(s):  
Organic Carbon ◽  
Common Bean ◽  
Microbial Biomass Carbon ◽  
Soil Classification ◽  
Soil Samples ◽  
Total Carbon ◽  
Carbon Pools ◽  
Organic Matter Fractions ◽  
The Impact ◽  
Organic Compost

In 1984, a field experiment was initiated in Coimbra, State of Minas Gerais, Brazil, involving the combination of 3 levels of mineral fertilisers at control (0); 10 kg N/ha, 15 kg P/ha, and 17 kg K/ha (MF1); 20 kg N/ha, 30 kg P/ha, and 34 kg K/ha (MF2); and 2 levels of organic compost at control (0) and 40 m3/ha (OC) in a maize/common bean intercrop. Soil samples were collected (0–0.10 and 0.10–0.20 m) in 2000 to evaluate the impact of mineral and organic compost on total carbon (TOC) and nitrogen (TN) stocks and on organic carbon pools of a Ferric Acrisol (Chromosol in the Australian Soil Classification). Additional soil samples were collected from an adjacent site covered by secondary Atlantic Forest as a reference. The conversion of forest to agriculture caused a reduction in most of TOC, TN, and microbial biomass carbon, free-light fraction carbon (CLF), and non-labile carbon. The carbon pools in cultivated plot were enhanced by the addition of compost alone. At both depths, TOC and TN stocks were higher (P < 0.05) in the MF2 + OC than MF2 treatment. Compared to soils that have received mineral fertiliser alone or combined with compost, the stocks of labile organic carbon, TN, and CLF were significantly affected (P < 0.05) by the sole application of compost.

Synthesis and Characterization of Poly(p-phenylene ethynylene)s with nitroxyl radical endgroups

2012 ◽  
Vol 1403 ◽  
Author(s):  
Michael Schroeter ◽  
M. Behl ◽  
C. Weder ◽  
A. Lendlein
Keyword(s):  
Nitroxyl Radical ◽  
Coupling Reaction ◽  
Hydroxyl Groups ◽  
Phenylene Ethynylene ◽  
New Approach ◽  
H Nmr ◽  
Sonogashira Coupling Reaction ◽  
Enhanced Conductivity ◽  
Additional Charge

ABSTRACTThe generation of terminal N-Hydroxyl substituents in p-phenylene ethynylene based compounds is presented. P-phenylene ethynylene derivatives were synthesized in a Sonogashira coupling reaction. N-Hydroxyl groups could be introduced by lithiation of iodine moieties and subsequent reaction with the 2-methyl-2-nitrosopropane generated by the cleavage of its dimer. The synthesis by lithiation was found to be more effective compared to the reaction with the Grignard reagent and the chloro-derivative. The resulting compounds were characterized by 1H NMR, UV and PL spectroscopy and were shown to be sensitive towards oxidation. This new approach of introducing additional charge carriers by nitroxyl endgroups might enable conjugated polymers with enhanced conductivity.

Dynamics of selected chemical and microbiological properties changes in soils after application of ultra-fine powdered calcium carbonate – incubation studies

2020 ◽  
Author(s):  
Karolina Woźnica ◽  
Michał Gąsiorek ◽  
Justyna Sokołowska ◽  
Agnieszka Józefowska ◽  
Tomasz Zaleski
Keyword(s):  
Calcium Carbonate ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Soil Properties ◽  
Carbon Content ◽  
Buffer Capacity ◽  
Microbial Biomass Carbon ◽  
Soil Samples ◽  
Organic Carbon Content ◽  
Biomass Carbon

&lt;p&gt;Soil acidification is a serious problem on a global scale, about 30% of land surface is occupied by acidic soils (pH&amp;#8804; 5.5). Recent research indicates, that more than 50% of arable soils in Poland have too low pH. Acid soils are characterised the ability to mobilize toxic metals and increased plant uptake as well as decreased microbial activity in the soil. Progressive acidification leads to degradation of soils and caused that they are marginal for agricultural production. Soil acidification is a naturally occurring process, but only when natural factors are supported by intensive human activity, especially by nitrogen fertilisers application, intensive degradation is observed. Traditionally method to increase soil pH is the application of lime materials e.g. calcite, burnt lime or dolomite. The liming efficiency depends on lime material type (primarily chemical form of calcium compounds), the neutralising value, lime application method, soil properties and the particle size distribution of lime. The aim of this research was to determine the rate of action and influence of ultra-fine powdered calcium carbonate on selected chemical and microbiological soil properties.&lt;/p&gt;&lt;p&gt;The incubation studies were conducted on the three soils (G1, G2 &amp;#8211; silt loam and G3 &amp;#8211; sandy loam). Soil samples were taken from the 0-20 cm layer. Soil properties were measured after 7, 14, 30, 60 and 120 days of incubation. The liming factor was ultra-fine powdered calcium carbonate with particle size distribution &lt; 0.08 mm. The application dose was calculated for 0.5 soil hydrolytic acidity. In the soil samples pH&lt;sub&gt;KCl&lt;/sub&gt;, buffer capacity, microbial biomass carbon and dissolved organic carbon content were measured.&lt;/p&gt;&lt;p&gt;Application of lime caused an increase of pH value in all studied soils. The highest increase of the pH&lt;sub&gt;KCl &lt;/sub&gt;was noted between 0 to 7&lt;sup&gt;th&lt;/sup&gt; day of incubation. Afterward, the pH&lt;sub&gt;KCl &lt;/sub&gt;decreased slowly for the soil G1 and G2. However, in the soil G3 significantly decreased just after 7&lt;sup&gt;th&lt;/sup&gt; to 14&lt;sup&gt;th &lt;/sup&gt;day, and afterward, the pH&lt;sub&gt;KCl&lt;/sub&gt; decreased slowly to the end of the incubation period. As a result of liming long-term changes in soil buffer capacity were not noted. The studied soils were characterised by the higher buffer capacity in alkaline than in acidic range. The microbial biomass carbon content was varied during the incubation in all studied soils. The dissolved organic carbon content increased during the incubation, starting from the 7&lt;sup&gt;th&lt;/sup&gt; to the 120&lt;sup&gt;th&lt;/sup&gt; day of incubation for G2 and G3 soils and from 14&lt;sup&gt;th &lt;/sup&gt;to last day of incubation for G1 soil. Application of lime caused an increase of the dissolved organic carbon content in all studied soils. These studies show that application of ultra-fine powdered calcium carbonate is an effective and fast way to improve soil properties.&lt;/p&gt;

scholarly journals Microbiological parameters of soil set aside before and after desiccation

2011 ◽  
Vol 52 (No. 3) ◽  
pp. 97-104
Author(s):  
M. Nováková ◽  
K. Voříšek
Keyword(s):  
Organic Carbon ◽  
Microbial Biomass Carbon ◽  
Soil Samples ◽  
Perennial Grasses ◽  
Actual Content ◽  
Before And After ◽  
Microbiological Parameters ◽  
Underground Biomass ◽  
Glyphosate Herbicide ◽  
Positive Effect

Herbaceous cover of luvic chernozem (seven years set aside) with legumes, perennial grasses and their mixture was desiccated by the glyphosate herbicide Roundup Biaktiv (5 l/ha at July 2003 and 4 l/ha at June 2004). 165 soil samples were collected before (November 2002&ndash;July 2003) and after desiccation (September 2003&ndash;August 2004). Desiccation had a strong positive effect on immobilization of organic carbon from herbaceous cover and underground biomass to microbial biomass carbon (MBC) and to soil organic carbon (C<sub>org</sub>), respectively. A significant increase after desiccation (p &lt; 0.01) was confirmed in the parameters: C<sub>org</sub>, MBC and in the ratio MBC/C<sub>org</sub>. At the same time the desiccation had a retardation effect on mineralization of C<sub>org</sub>, N<sub>org</sub> and S<sub>org</sub>. A significant decrease after desiccation (p &lt; 0.01) was confirmed in the basal and potential respiration (with nitrogen, with nitrogen and glucose), actual content of N-NH<sub>4</sub><sup>+</sup> without and with pre-incubation, control ammonification, and (p &lt; 0.05) in arylsulphatase activity. The actual content of NO<sub>3</sub><sup>&ndash;</sup> and the control nitrification increased significantly (p &lt; 0.01) after desiccation. Plots management before desiccation included black and spontaneous fallow, mulching (one or two per year) and cutting (three times per year), plots with 4 legumes, 4 grasses and their mixtures. Mulching variants showed the best results both before and after desiccation. The soils with cutting treatment ranked 8<sup>th</sup>&ndash;10<sup>th</sup> out of 11&nbsp;studied combinations.

scholarly journals Synthesis and Characterization of Aza-Trimetalla Tetrahedranes

1996 ◽  
Vol 51 (11) ◽  
pp. 1621-1626 ◽  
Author(s):  
Max Herberhold ◽  
Uwe Bertholdt ◽  
Bernd Wrackmeyer
Keyword(s):  
Nitrogen Atom ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Double Resonance ◽  
Synthesis And Characterization ◽  
Exchange Reactions ◽  
H Nmr ◽  
A Minor

The sulfimide complex Fe2(CO)6(μ-SNH) (1) reacts with Co2(CO)8 to form a 1:1 mixture of the known clusters FeCo2(CO)9(μ3-S) (2) and FeCo2(CO)9(μ3-NH) (3). The azatetrahedrane 3 may be used as a precursor for the synthesis of the new aza-trimetalla tetrahedranes Fe2Co(CO)9(μ-H)(μ3-NH) (5), CpMoFeCo(CO)8(μ3-NH) (6), CpNiFeCo(CO)6(μ3-NH) (7) and (CpNi)2Fe(CO)3(μ3-NH) (8) which were obtained from exchange reactions of 3 with Na2[Fe(CO)4], Na[CpMo(CO)3] and [CpNi(CO)]2. However, the reactions of 3 with Na2[Fe(CO)4] and Fe3(CO)12 gave Fe3(CO)9(μ-H)2(μ3-NH) (9) only as a minor product in addition to large amounts of Fe3(CO)9(μ-H)2(μ3-S) (10). The 1H NMR spectra of 3 and 5 - 9 show a broadened triplet for the NH proton between δ(1H) 8.21 and 9.53. Chemical shifts δ(14N) were determined most efficiently by heteronuclear 1H {14N} double resonance experiments. The δ(14N) values for aza-trimetalla tetrahedranes (-180 to -202) indicate delocalized bonding between the μ3-bridging nitrogen atom and the metal triangle.

scholarly journals SPECTROSCOPIC CHARACTERIZATION OF HUMIC SUBSTANCES OF ANTHROPOGENIC SOILS DERIVED FROM TERRA ROSSA

AGROFOR ◽  
2016 ◽  
Vol 1 (3) ◽  
Author(s):  
Aleksandra BENSA ◽  
Boško MILOŠ ◽  
Nikolina JURKOVIĆ BALOG ◽  
Ivana TORIĆ
Keyword(s):  
Organic Carbon ◽  
Humic Substances ◽  
Spectroscopic Characterization ◽  
Soil Samples ◽  
Soil Horizon ◽  
Anthropogenic Soils ◽  
Terra Rossa ◽  
Humus Quality

The aim of the study was spectroscopic characterization of humic substances andevaluation of humus quality of anthropogenic soils derived from Terra Rossa. Thestudy was conducted on 15 soil samples collected from top-soil horizon of olivegroves in Middle Dalmatia (Croatia). Total organic carbon was determinedaccording to Walkley-Black method (1934) and humic substances isolationfollowing procedure given by Schnitzer (1982). Spectroscopic characterization ofisolated humic substances was carried out by measuring absorbance in VIS spectralrange 400-700 nm and optical indices (Q4/6, E4/6) were calculated. SOC content intop-soil samples varied from 1.45% to 4.21% with mean value of 2.98%. Theabsorption spectrum showed monotonous decrease of absorbance from 400 to 700nm for all samples. The optical indices E4/6 and Q4/6 varied from 3.58 to 5.05 andfrom 3.91 to 5.04, respectively and indicated differences of humus quality. Theoptical index below 4, which implies a high quality of humus, was determined insix samples. The low humus quality (optical index above 4) was determined inother nine samples. The SOC content has significant positive correlation withoptical indices Q4/6 and E4/6. Soils with higher organic carbon content have lowerhumus quality.

Synthesis and characterization of new porphyrin/β-cyclodextrin derivatives covalently connected by aliphatic chains of different length

2016 ◽  
Vol 20 (06) ◽  
pp. 700-707
Author(s):  
Giuseppa Mercorillo ◽  
Roberta Puglisi ◽  
Emanuela Spina ◽  
Daniele Vitalini
Keyword(s):  
Mass Spectrometry ◽  
Chain Length ◽  
Water Solubility ◽  
Synthesis And Characterization ◽  
Cyclodextrin Derivatives ◽  
H Nmr ◽  
Vis Spectroscopy ◽  
Covalently Linked ◽  
Aliphatic Chains

Covalently linked porphyrin/β-cyclodextrin derivatives have been synthesized by reaction between 5,10,15-tris-{p-[9-methoxy-tris-(ethyleneoxy)-phenyl]}-20-(p-hydroxyphenyl)-porphyrin, β-cyclodextrin-6-alcoholate and di-brominated aliphatic chains of different length, and characterized by MALDI-TOF mass spectrometry, 1H NMR and UV-vis spectroscopy. As a function of chain length, these compounds exhibit different degrees of water solubility, becoming higher with increasing chain length. The lack of self-assemblies between porphyrins and β-cyclodextrins (which renders the two sub-units completely free to perform their activities) and their water solubility, make these compounds excellent candidates in fields like drug-delivery or photodynamic therapy.

scholarly journals Chemical and microbiological characterization of Cambisols, Luvisols and Stagnosols

2009 ◽  
Vol 55 (No. 6) ◽  
pp. 231-237 ◽  
Author(s):  
L. Růžek ◽  
M. Růžková ◽  
K. Voříšek ◽  
J. Kubát ◽  
M. Friedlová ◽  
...  
Keyword(s):  
Microbial Biomass Carbon ◽  
Dry Mass ◽  
Soil Samples ◽  
Total Carbon ◽  
Water Addition ◽  
Soil Extracts ◽  
The Czech Republic ◽  
S 100 ◽  
Microwave Sterilization

Cambisols, Luvisols and Stagnosols are main soil taxonomical units covering 78% of the total area of the Czech Republic. In the period 2001–2008 soil samples from 13 arable and 2 grassed localities were collected and tested. Microbial biomass carbon (MBC) was determined using microwave irradiation method (MW), chloroform fumigation extraction method (FE) and re-hydration technique (RHD). Soil samples were moistened, according to the content of organic carbon (C<sub>org</sub>), by deionized water addition (%C<sub>org</sub> × 0.19 ml/g DM – dry mass of soil) immediately before MBC determination. Microwave sterilization (800 J/g DM = 600 W, 2 × 67 s, 100 g DM (10 soil samples) and microwave soil extracts digestion (800 J/ml = 250 W, 77 s, 24 ml) give the lowest values of MBC (204 ± 67 mg/kg DM; 100%) in comparison with FE (236 ± 57 mg/kg DM; 116%) and RHD (478 ± 138 mg/kg DM; 235%), respectively. High significant correlation (<i>r</i> = 0.9713) was found between TC (total carbon; 1.36 ± 0.29%) and TN (total nitrogen; 0.15 ± 0.03%) determined by CNS analyzer. Furthermore, high significant correlations were found between MBC-MW and MBC-RHD (<i>r</i> = 0.8965) as well as MBC-FE and DHA (dehydrogenase activity; <i>r</i> = 0.8094), respectively. DHA in studied soils reached 147 ± 68 mg of triphenylformazan/kg DM/24 h. C<sub>org</sub> formed 96% of TC and total Kjeldahl nitrogen 97% of TN, respectively. According our results MW is fully acceptable for MBC determination.

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