Amine Composition Research Articles

Refrachor (F) – seventy-year-old tool and a contemporary observation: estimation of equilibrium compositions of 1H- and 2H-tautomers of tetrazole and 1,2,3-triazole and imine–amine composition of acetaldimine–vinylamine tautomerism

Abstract Refrachor with a symbol F a new physical constant proposed for the first time in 1951 by Joshi and Tuli defined by the equation F = –P log( n D 20 ${n}_{\mathrm{D}}^{20}$ –1) where P is the parachor and n D 20 ${n}_{\mathrm{D}}^{20}$ is the refractive index, is now used in our present work to calculate the percentage composition of 1H- and 2H-tautomers of tetrazole, 1,2,3-triazole, and imine-enamine tautomerism of acetaldimine in their equilibrium mixtures.

Heat storage and release in binary paraffin-hexadecyl amine composites for solar greenhouses in cold climates

Traditional solar greenhouses in cold regions of China often suffer from poor thermal insulation and storage capacity, resulting in inefficient use of solar energy resources and reduced crop production efficiency. Therefore, it is crucial to explore methods to enhance the thermal conditions within these greenhouses. This paper proposes incorporating a “binary paraffin hexadecyl amine” phase change material into concrete, creating a novel composite material for use in a phase change thermal storage concrete slab. This approach can effectively address the previously mentioned issues. Two solar greenhouses were constructed to directly observe the material's impact on the thermal environment within a greenhouse. One greenhouse was equipped with the phase-change thermal storage slab, while the other served as a control greenhouse without the slab. Temperature field test was conducted on both greenhouses, and the obtained test data demonstrated the temperature regulation advantages of the phase-change greenhouses. Tomatoes were concurrently cultivated in both structures, and a temperature test was conducted to assess the phase-change heat-storage slab's influence on temperature regulation. The results indicate that, compared to similar studies, the phase-change heat-storage slab employed in this study demonstrates superior temperature regulation capabilities. It raises the average greenhouse temperature by 4.2 °C during winter, storing 8.85 × 104 kJ/m3 of heat per unit volume, which is 1.5 to 2.8 times higher than existing materials in the same category. In sunny conditions, the phase-change greenhouse exhibited a 4.9 °C reduction in maximum indoor temperature during the day and a 3.5 °C increase in minimum indoor temperature at night compared to the control greenhouse. This indicated that the phase-change heat storage slab acted as a heat buffer, effectively regulating the temperature inside the solar greenhouse. Tomatoes experienced a 26.6 % increase in effective accumulated temperature, resulting in maturation period occurring 13.04 % earlier compared to the control greenhouse.

Enantiomer Recognition Based on Chirality Transfer from Chiral Amines to Ternary Dynamic Covalent Systems.

Enantiomer recognition is usually required in organic synthesis and materials and life sciences. This paper describes an enantiomer recognition method based on ternary dynamic covalent systems constructed via the complexation of chiral amines with a chiral boronate derived from 1,4-phenylenediboric acid and an L-DOPA-modified naphthalenediimide. The ternary systems aggregate into chiral assemblies driven by π-π interactions, and the chirality is transferred from the chiral amines to assemblies with high stereospecificity. Consequently, the enantiomer composition of chiral amines and the absolute configuration of the major enantiomer can be determined according to the sign of the Cotton effect of the ternary system by using circular dichroism (CD) spectroscopy. This method offers the advantage of using the long wavelength CD signals of the boronate at around 520 nm, thereby avoiding interference with those of the carbon skeleton. This ternary system provides a novel approach to the design of enantiomer recognition systems.

Nutritional characterisation of homemade beef sausage based on amino acid, biogenic amines, and fatty acid composition

AbstractThe aim of this study was to assess the nutritional quality of homemade beef sausages by examining the amino acid, biogenic amine, and fatty acid composition. The most abundant amino acids were Ala (15.56%), Leu (13.28%), Gly (8.64%), Pro (8.41%), Ser (8.26%), and Val (7.65%). The essential amino acids accounted for 44.30% of total amino acids. Apart from the protein building amino acids, the free amino acid content was relatively high, accounting for 10% of total amino acid content. The average biogenic amine concentration in the sausage samples was low (1.69 mg kg−1). Saturated fatty acids accounted for 59.10% of total fatty acids, followed by monounsaturated (38.63%) and polyunsaturated fatty acids (2.27%). The fatty acid profile was dominated by oleic (C18:1, 34.37%) and palmitic (C16:0, 30.24%) acids, and short-chain fatty acids were also present, which may have a positive impact on gut health. The results show that beef sausages have a high nutritional value and are a good source of essential amino acids, free amino acids, and fatty acids that are important for human health.

Comparative Analysis of Amino Acid and Biogenic Amine Compositions of Fermented Grape Beverages.

Amino acids and biogenic amines are important components of food and beverages. In grape-derived products such as wine and wine vinegar, they can have different origins and can influence the odor and taste of the products. Their concentration is influenced by the grape variety, vintage, and winemaking process. In our study, we carried out an LC-MS-based comparative analysis of 22 grape-derived beverages, including three different wine types and four wine vinegar samples from the Tokaj region in Hungary. The concentrations of 23 amino acids and 10 biogenic amines were examined, and the differences among the sample types were analyzed. The differences in the concentrations of some metabolites between Aszú-Furmint pairs originating from the same wineries and year provide information on the effect of botrytized grape on wine composition. Our data can provide further evidence on how the production process shapes the metabolite content of beverages and highlight the nutritional value of wine vinegar.

Characteristics, Origins, and Atmospheric Processes of Amines in Fine Aerosol Particles in Winter in China

AbstractAmines affect particle formation, aerosol acidity, nitrogen cycle, and climate change. However, little is known about the temporal and spatial differences in the composition, source, and formation process of amines in fine particulate matter (PM2.5) in different regions of China. Seven amines (amine salts) were investigated in PM2.5 collected in the Yangtze River Delta (YRD, Shanghai and Nanjing), Pearl River Delta (PRD, Guangzhou), northern China (Xi'an and Haerbin), and background (Puding) areas in winter 2017–2018. Methylamine was the dominant amine species at the YRD, northern China, and background sites, while diethylamine dominated at the PRD site; moreover, the mass concentration and fraction of diethylamine were the lowest at the background site. These results could be attributed to changes in sources and atmospheric processes. Further, coal combustion and biomass burning were found to be important contributors of amines in northern cities in winter. The contribution of biomass and coal combustion to amines was weakened in other urban sites. In contrast, the amine abundance at the background site was largely controlled by biogenic sources. Acid‐base chemistry and displacement mechanism were tightly associated with the formation of amine salts at all sites. In particular, the atmospheric degradation of amines by hydroxyl radical (•OH) was significant at the Nanjing, Guangzhou, Xi'an, and Haerbin sites. The insignificant photochemical degradation of amines at the Shanghai and background sites can be explained by differentiated amine sources, meteorological conditions, and •OH levels. Overall, our findings deepen the understanding of the origins and atmospheric processes of amines.

Selective removal of ammonia from wastewater using Cu(II)-loaded Amberlite IR-120 resin and its catalytic application for removal of dyes

Cationic ligand exchange is one of the most predominant mechanisms for the removal of ammonia from wastewater through complex formation. The complexation technique occurs between the metal ions loaded on the surface of Amberlite IR-120 and ammonia which is present in the medium. Cu(II)-loaded Amberlite IR-120 (R-Cu2+) was prepared and described using FT-IR, TGA, SEM, and EDX techniques. The prepared R-Cu2+ was applied for the elimination of ammonia from an aqueous solution. Different cations such as Co2+ and Ni2+ were loaded onto Amberlite IR-120 to study the impact of counter cation on the removal efficiency of ammonia. The ammonia removal percentage followed the order; R-Cu2+ > R-Ni2+ > R-Co2+. The effects of contact time, pH, initial concentration, temperature, and coexisting ions on the removal of ammonia from wastewater by R-Cu2+ were investigated. The equilibrium adsorbed amount of ammonia was found to be 200 mg/g at pH = 8.6 and 303 K within 60 min using 0.1 g R-Cu2+ and an initial concentration of ammonia of 1060 mg/L. The removal of ammonia using R-Cu2+ obeyed the non-linear plot of both Freundlich and Langmuir isotherms. According to the thermodynamic parameters, the adsorption of ammonia onto R-Cu2+ was an endothermic and spontaneous process. The time-adsorption data followed the pseudo-second-order and intraparticle diffusion models. Moreover, the resulting product (R-Cu(II)-amine composite) from the adsorption process exhibited high catalytic activity and could be low-cost material for the elimination of dyes such as aniline blue (AB), methyl green (MG), and methyl violet 2B (MV2B) from wastewater.Graphical

Changes in Biogenic Amines of Two Table Grapes (cv. Bronx Seedless and Italia) during Berry Development and Ripening.

Bronx Seedless and Italia (Vitis vinifera L.) are a variety preferred by consumers owing to their exciting flavour and widely cultivated in Aegean Region in Turkey. The aim was to identify the biogenic amines of these table grapes during berry ripeness. The biogenic amines were analyzed by HPLC in six different berry phenological stages. Italia grapes presented lower biogenic amine content than Bronx Seedless table grapes. The concentration of most of the biogenic amines analyzed linearly raised from the beginning of berry touch to when berries ripen for harvest stages. The most common biogenic amines in grape varieties were putrescine, followed by histamine, agmatine, and tyramine. There was also a positive correlation between all biogenic amines of the two grape varieties. The weakest correlation was found between spermine and cadaverine, whereas the strongest correlation was found among dopamine, trimethylamine, norepinephrine, tyramine, and histamine amines. The present study is the first report of a synthesis study regarding the effect of B.A.s on quality characteristics throughout berry ripeness in grape varieties containing foxy and muscat tastes. The concentration and composition of biogenic amines identified for both varieties might provide helpful information regarding human health and the vintage.

Rooibos (Aspalathus linearis) alters secretome trace amine profile of probiotic and commensal microbes in vitro

Ethnopharmacology relevanceAspalathus linearis (Burm.f.) R. Dahlgren (rooibos) tea is anecdotally renowned for its calming effect in the context of gastrointestinal discomfort, but little scientific support is available to elucidate potential mechanisms of action. Enhancement of dietary polyphenol content to improve gut health via prebiotic-like modulation of the gut microbiota has gained significant research interest. Given the known high polyphenol content of rooibos, rooibos tea may potentially exert a prebiotic effect in the gut to facilitate an improvement in chronic inflammatory gastrointestinal conditions.Aim of the study: This study aimed to determine the prebiotic or health-modulating potential of rooibos tea in terms of its effect on gut microbial growth and secretome trace amine composition, as well as to determine how differential rooibos processing alters this activity. MethodsThree rooibos preparations (green and fermented leave aqueous extracts, as well as a green leaf ethanol extract) were compared in terms of their phenolic composition (qTOF-LC/MS). Moreover, the effect of rooibos exposure on growth and secretome trace amine levels of probiotic and commensal microbes were assessed (LC/MS). In addition, given the known female bias prevalent for many gastrointestinal disorders, experiments were conducted in the absence and presence of estradiol. ResultsPolyphenolic composition of rooibos was drastically reduced by fermentation. Aqueous extracts of both green and fermented rooibos improved microbial growth, although fermented rooibos had the most pronounced effect (p < 0.01). In terms of secretome trace amine profile, both aqueous extracts of rooibos seemed to facilitate increased putrescine secretion (p < 0.0001) and decreased tryptamine production (p < 0.0001). Estradiol seemed to suppress trace amine secretion by bacteria (Lactobacillus plantarum, Lactobacillus reuteri and Enterococcus mundtii) but increased it in yeast (Saccharomyces boulardii). ConclusionRooibos altered gut probiotic and commensal microbial growth and secretome trace amine profiles in vitro, suggesting it has potential to modulate gut microbial composition and functionality as a prebiotic. Current data suggest that these effects are highly dependent on raw material processing. Finally, rooibos may be able to prevent estradiol-associated alterations in trace amine profile, which may have important implications for patient management in female-predominant gastrointestinal disorders.

Hydroxypropyl methylcellulose (HPMC) reduces the hardening of fructose-containing and maltitol-containing high-protein nutrition bars during storage

In this study, high-protein nutrition bars (HPNBs) were prepared using sodium caseinate and either fructose or maltitol as raw materials. The effects of the incorporation of hydroxypropyl methylcellulose (HPMC) on the hardness and physicochemical changes of HPNBs during storage were evaluated. Both HPNB systems containing HPMC exhibited significantly lower hardness than the control HPNBs (no HPMC) during storage, and the change in hardness was dependent on the concentration of HPMC added. The incorporation of 2% HPMC reduced the hardness of the fructose-containing and maltitol-contianing HPNBs by 44.83% and 27.89%, respectively, after 35 days of storage. The addition of HPMC inhibited Maillard reactions within the fructose-containing HPNBs, which exhibited little changes in the total color and composition of free amines. HPMC also significantly mitigated the increase in the insoluble protein content and the transformation of β-turn to β-sheet in proteins that were observed in both HPNB systems during storage. Scanning electron microscopy also confirmed that the texture of the HPNB containing HPMC changed less during storage compared to the controls. These results indicated that HPMC could be used as an inhibitor to reduce the extent of Maillard reactions and protein aggregation during food storage.

Large contributions of anthropogenic sources to amines in fine particles at a coastal area in northern China in winter

Amines in fine particles constitute a significant fraction of secondary organic aerosols and have adverse effects on air quality and human health. To understand the chemical composition, variation characteristics, and potential sources of fine particulate amines in the coastal area in northern China, field sampling and chemical analysis were conducted in coastal Qingdao in the winter of 2018 and 2019. A total of 15 major amines were identified and quantified by using an ultra-high-performance liquid chromatography coupled with mass spectrometry. The average concentration of total amines in PM2.5 samples was approximately 130 ng m−3. Dimethylamine was the most abundant species with average fractions of 44.8% and 65.0% in the quantified amines during the two field campaigns, followed by triethylamine (22.9% and 8.7%) and methylamine (8.3% and 4.4%). The amines in PM2.5 usually exhibited elevated concentrations in the presence of high levels of SO2 and NOx or in the condition of high relative humidity. A receptor model of positive matrix factorization was employed and seven major sources were identified, including coal combustion, industrial production, vehicle exhaust, biomass burning, agricultural activities, secondary formation, and marine emission. Surprisingly, most of 15 amines in fine particles primarily originated from the primary emissions of anthropogenic activities particularly related to coal combustion and industrial productions, which should be given close concern to address the amine pollution.

Chemical composition and sources of amines in PM2.5 in an urban site of PRD, China

Atmospheric amines have attracted increasing attention due to their significant impact on new particle formation, particle hygroscopicity and particle optical properties. In this study, four low-molecule-weight amines were detected from PM2.5 filter samples collected at an urban site of Pearl River Delta (PRD) region of China in 2018 autumn. During the campaign, the mass concentrations of ambient particulate methylamine (MA, CH3NH2), dimethylamine (DMA, (CH3)2NH), trimethylamine (TMA, (CH3)3N), and diethylamine (DEA, (C2H5)2NH) were quantified at daily or 12-h resolution using an optimized Ion Chromatograph (IC) method. The total measured amine concentration was 297 ± 209 ng/m3, which can account for 0.76 ± 0.33% of PM2.5 mass concentrations. The particulate amines in PRD urban area were dominated by MA (243 ± 179 ng/m3), accounting for over 80% of total amines, then followed by DMA (49 ± 30 ng/m3, 16.5%), TMA (4 ± 2 ng/m3) and DEA (1 ± 1 ng/m3). Based on the correlation analysis, MA and DMA mainly presented as nitrate and sulfate salts. We speculate the amines tend to react with gas-phase HNO3 or particle-phase nitrate to form particulate amine salts via local process in Guangzhou. As the relative humidity (RH) increased, enhanced partitioning of amine towards the particle phase was observed. Using approach of multiple linear regression, 71% of the particulate amines in PRD urban site could be explained by acid-base process and the rest by primary emissions from combustion sources (29%).

Data Fusion Approaches for the Characterization of Musts and Wines Based on Biogenic Amine and Elemental Composition.

Samples from various winemaking stages of the production of sparkling wines using different grape varieties were characterized based on the profile of biogenic amines (BAs) and the elemental composition. Liquid chromatography with fluorescence detection (HPLC-FLD) combined with precolumn derivatization with dansyl chloride was used to quantify BAs, while inductively coupled plasma (ICP) techniques were applied to determine a wide range of elements. Musts, base wines, and sparkling wines were analyzed accordingly, and the resulting data were subjected to further chemometric studies to try to extract information on oenological practices, product quality, and varieties. Although good descriptive models were obtained when considering each type of data separately, the performance of data fusion approaches was assessed as well. In this regard, low-level and mid-level approaches were evaluated, and from the results, it was concluded that more comprehensive models can be obtained when joining data of different natures.

Brewing and the Chemical Composition of Amine-Containing Compounds in Beer: A Review.

As microbreweries have flourished and craft beer brewing has expanded into a multibillion-dollar industry, the ingredients and techniques used to brew beer have changed and diversified. New brewing ingredients and techniques have led to increased concern over biogenic amines in the final product. Biogenic amine composition and concentration in beer, as well as the changes to the protein and amino acid content when adjuncts are used, have received little attention. A complex biochemical mixture, the proteins, amino acids, and biogenic amines undergo a variety of enzymatic and non-enzymatic catabolic, proteolytic, and oxidative reactions during brewing. As biogenic amines in fermented food receive increased scrutiny, evaluating knowledge gaps in the evolution of these compounds in the beer brewing process is critical.

Analisis dan Optimasi Pengaruh Suhu Gas Umpan Pada Kinerja Acid Gas Removal Unit

The Gas Gathering Station (GGS) in field X processes gas from 16 (sixteen) wells before being sent as selling gas to consumers. The sixteen wells have decreased in good pressure since 2011, thus affecting the performance of the Acid Gas Removal Unit (AGRU). The GGS consists of 4 (four) main units, namely the Manifold Production/ Test, the Separation Unit, the Acid Gas Removal Unit (AGRU), the Dehydration Unit (DHU). The AGRU facility in field X is designed to reduce the acid gas content of CO2 by 21 mol% with a feed gas capacity of 85 MMSCFD. A decrease in reservoir pressure caused an increase in the feed gas temperature and an increase in the water content of the well. Based on the reconstruction of the design conditions into the simulation model, the amine composition consisting of MDEA 0.3618 and MEA 0.088 wt fraction to obtain the percentage of CO2 in the 5% mol sales gas. The increase in feed gas temperature up to 146 F caused foaming due to condensation of heavy hydrocarbon fraction, so it was necessary to modify it by adding a chiller to cool the feed gas to become 60 F. Based on the simulation, the flow rate of gas entering AGRU could reach 83.7 MMSCFD. There was an increase in gas production of 38.1 MMSCFD and condensate of 1,376 BPD. Economically, the addition of a chiller modification project was feasible with the economical parameters of NPV US$ 132,000,000, IRR 348.19%, POT 0.31 year and PV ratio 19.06.

Role of Nano-Sized Graphene Amine Reinforcements in Mechanical Properties of AA7076 Based MMCs

Aims: AA7076 is a well-defined alloy for its excellent physical and mechanical properties such as high strength, toughness, and low density. To meet the requirements of the automobile and aerospace industry, the properties of AA7076 alloy have to be improved by reinforcing nano-sized graphene amine particles. Objective: The aim of this study is to synthesize and characterize the AA7076 alloy reinforced with graphene nanofillers for different structural engineering applications. Methods: In this present work, nano-sized graphene amine particles were added and dispersed homogeneously using a motorized stir casting technique. AA7076/graphene amine composites were prepared by varying wt.% percent of graphene amine reinforcement particles (0.5, 0.75, 1, and 1.25 wt.% (weight-percentage)). Results: The SEM micrographs reveal the homogeneous distribution of graphene amine reinforcements along the grain boundaries of the AA7076 matrix material. The experimental test results showed that with the addition of graphene amine reinforcements, the mechanical properties of the AA7076/graphene amine composites improved as compared to the AA7076 matrix material. Conclusion: The composite with 1 wt.% graphene amine showed higher strength and hardness as compared to other reinforcements.

Effect of Mechanical Properties in Enhanced Polymeric Blend Membranes

This study was carried out to evaluate the effect of blending the rubbery and glassy polymer with an alkanolamine on the mechanical properties. Due to the intrinsic properties of glassy polysulfone (PSU) and rubbery polyvinyl acetate (PVAc), optimizing their properties by blending both polymers is expected to address the shortage. The enhanced polymeric blend membrane (EPBM) was developed by varying the composition of PVAc ranging from 5 to 20 wt. % with 95 to 80 wt. % base PSU in dimethyl- acetamide (DMAc) solvent. The DEA amine composition was added to the blend and kept at 10 wt. % over solvent. The tensile analysis technique is utilized to evaluate the mechanical behaviour of a polymeric material which comprises the deformation of the polymeric material underneath the effect of an applied force prior to failure. The mechanical analysis showed improvement in tensile strength, Young's modulus and elongation at break properties with the increase in PVAc/DEA composition in the enhanced polymeric blend membranes. The elongation at break property increased with an increase in the amine contents which indicated the flexibility of the EPBM. In addition, the mechanical analysis revealed remarkable enhancement in the mechanical properties of the EPBM which might be attributed to the robust interactions among the PSU blend with PVAc and DEA.

Methanolysis of duckweed and azolla: A comparative analysis

This paper compares the bio-oil and chemical compositions produced from methanolysis of duckweed and Azolla. The methanolysis was carried out at 230°C, 250°C and 300°C for 30 minutes using the CJF-0.1L reactor. Oil yield produced from azolla was 34% and this is 3% higher as compared to the bio-oil yield produced by duckweed at 250°C. The Gas Chromatography Mass Spectrometry (GCMS) analysis showed that alcohol, ketone, amine, ether and ester compositions in the bio-oil produced from duckweed were slightly higher than azolla. However, carboxylic acids, amide and phenol compounds in the bio-oil produced from azolla are different and higher than duckweed. The results suggest that duckweed and azolla are the potential feedstocks from aquatic biomass to be further investigated for bio oil use.

Effects of Amine Structures on Oxidative Degradation of Amine-Functionalized Adsorbents for CO2 Capture

A series of adsorbents containing different amines including diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, branched poly(ethylenimine), and spermine were exposed to flowing O₂ at accelerated temperatures of 80 and 100 °C. Herein, we evaluated the structural effects of amines on the stability of CO₂ adsorbents in dry and wet O₂-containing environments. Various techniques were used to characterize the adsorbents. The CO₂ adsorption capacity of the sorbents was drastically reduced after exposure to dry O₂-containing environments. Sorbents modified with amines with a high molecular weight and a long chain of alkyl linkers between amine functional groups exhibited high resistance to O₂. The viscosity of the amines played an important role in the oxidative stability of the amine composites as it affected the mass transfer of O₂ to the amine sites of the composites. Furthermore, we report for the first time that the presence of steam in O₂ medium could suppress or accelerate the oxidative degradation of amine-based CO₂ sorbents depending on the amine structure.

Amino acid and biogenic amine composition of Busha cattle milk

AbstractTo our knowledge, there is a lack of information on the nutrient composition of Busha cattle milk with special regard to its amino acid and biogenic amine contents. The Busha cattle breed is known to be highly resistant to various diseases and well-adapted to the extensive breeding conditions of the Balkan Peninsula. Busha cow milk contains an average of 13.47% dry matter, 4.34% fat, 3.72 % protein, and 4.32% lactose. Significant differences were detected (P &lt; 0.05) in the amino acid compositions of the milk of different Busha cattle strains of Kosovo. Glutamic acid, proline, leucine, aspartic acid, lysine, and valine represented 68% of the total amino acid content. Essential amino acids, branched-chain and sulphur-containing amino acids were found in substantial amounts in the milk samples. Among the biogenic amines, however, spermine (0.16 mg kg−1) and cadaverine (0.09 mg kg−1) were present in low concentrations. Due to these excellent qualities of the Busha cow milk, preservation of this cattle breed is of great importance. Developing sustainable and secured breeding and feeding programs for this endangered cattle breed of the Balkan Peninsula should also be a high priority.