Butylamine Research Articles

Experimental, theoretical and computational study of binary systems of alkanolamines and alkylamines with cyclohexanol at different temperatures

Density, ρ, speed of sound, u, and the difference in the temperature before and after the mixing process , ΔT, were measured for binary mixtures containing of cyclohexanol (CYC) + diethanolamine (DEA) or triethanolamine (TEA) or butylamine (BUT) or hexylamine (HEX) at (303.15–318.15) K except ΔT at 303.15 K. The excess molar volume, VmE, excess partial molar volume, Vm,iE, excess thermal expansion coefficient, αE, isothermal coefficient of excess molar enthalpy,(∂HmE∂P)T,x, deviation in isentropic compressibility,Δκs, excess molar enthalpy,HmE, and excess partial molar enthalpy, Hm,iE, were also calculated. The calculated data were satisfactorily correlated by Redlich – Kister equation. Some empirical models such as (Prigogine–Flory–Paterson) PFP, Wilson, (Non-Random Two Liquid) NRTL and (universal quasi chemical) UNIQUAC. Computational methods were performed using density function theory (DFT) and molecular dynamics (MD) simulation and were used to discuss and compare intramolecular and intermolecular interactions. An acceptable agreement was found between empirical and theoretical data.

Exploration of Gas-Liquid Interfaces for Liquid Water and Methanol Using Extreme Ultraviolet Laser Photoemission Spectroscopy.

We present a study using extreme UV (EUV) photoemission spectroscopy of the valence electronic structures of aqueous and methanol solutions using a 10 kHz EUV light source based on high-order harmonic generation and a magnetic bottle time-of-flight electron spectrometer. Two aspects of the observed spectra are highlighted in this study. One is variation of the vertical ionization energy (VIE) for liquids as a function of the solute concentration, which is closely related to surface dipoles at the gas-liquid interface. The experimental results show that the VIE of liquid water increases slightly with increasing concentrations of NaCl and NaI and decreases with NaOH. The VIE of liquid methanol was also found to change slightly with NaI. On the other hand, tetrabutylammonium iodide (TBAI) and butylamine (BA) clearly reduce the VIE for liquid water, which is attributed to the formation of an electric double layer (EDL) by segregated solutes at the gas-liquid interface. As evidence for this, when the pH of an aqueous BA solution is reduced to protonate BA, the VIE shift gradually decreases because the protonated BA moves into the bulk to suppress the influence of the EDL. We computed the surface potentials for these solutions using molecular dynamics simulations, and the results supported our interpretation of the experimental results. Another observation is the variation of the relative energy and shape of individual photoelectron bands for solvents, which is related to alteration of the structure and constituents of the first solvation shell of ionized solvent molecules. All of the solutes cause changes in the photoelectron spectra at high concentration, one of the most prominent of which is the degree of splitting of the 3a1 band for liquid water and the 7a' band for liquid methanol, which are sensitive to hydrogen bonding in the liquids. The 3a1 splitting decreases with the increasing concentration of NaI, NaCl, and NaOH, indicating that Na+ penetrates into the hydrogen-bonding network to coordinate to a nonbonding electron of a water molecule. On the other hand, TBAI and BA cause smaller changes in the 3a1 splitting. Full interpretation of these spectroscopic features awaits extensive quantum chemical calculations and is beyond the scope of this study. However, these results illustrate the strong potential of EUV laser photoemission spectroscopy of liquids for exploration of interfacial and solution chemistry.

Switchable carbamate coagulants to improve recycling ionic liquid from biomass solutions

A reversible amine-carbamate approach has been developed to reduce the use of antisolvents such as water in the coagulation of biopolymers from ionic liquid (IL) solution and thus improve the economy of IL recycle. Cellulose and chitin were recovered from 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]) solution by introducing the miscible amines triethanolamine (TEA), ethylenediamine (EDA), or butylamine (BA) and bubbling CO2 at 40 °C and atmospheric pressure through the solutions to form carbamate salts in situ which resulted in biopolymer coagulation. BA gave the best results because of its low boiling point and low viscosity, which benefited both biopolymer recovery and IL recycle. Cellulose films and fibers could be formed by extrusion of an MCC/[C2mim]‐[OAc] solution into a coagulating bath comprised of a 1:1 M mixture of [C2mim][OAc] and butylammonium butylcarbamate (BA-carbamate). The cellulose, IL, amine, and CO2 were easily separated, although the cellulose recovered required some water washings to remove traces of IL. Up to 96.4% of the [C2mim][OAc] could be recovered, 76.2% from the coagulation bath and 20.2% from the water washings. The recycled IL was suitable for another cycle of cellulose dissolution and extrusion and 84.6% of the IL used for the second cycle was recovered. Although further work is needed, not the least of which will be reducing the amount of water needed for washing steps, some promising features of this process point the way for new directions for more economically viable IL recycling processes in biomass treatment with ILs.

Colorimetric Amine Detection by Vanillin-Hydrazone Derivatives during Chicken Meat Spoilage

Two vanillin-hydrazone compounds as the colorimetric amine detection during chicken meat spoilage are described. Two hydrazone compounds (1 and 2) have been synthesized from the condensation reaction of vanillin with phenylhydrazine and 2,4-dinitrophenylhydrazine. Their properties for colorimetric recognition of amine were determined by the naked eye and UV-vis spectra. Their properties as amine indicators were investigated toward primary amine: butylamine (BA); secondary amine: dimethylamine (DMA), diethylamine (DEA); tertiary amine: triethylamine (TEA), and also ammonia (Amm). The hydrazone 1 in DMSO showed no significant color changes (colorless) after the addition of amines solution. Hydrazone 2 (5×10-5 M in DMSO) showed color changes from yellow to violet in the presence of ammonia, DEA and BA, to reddish-violet for DMA, and light brown after addition of TEA solutions. The colorimetric amine detection by vanillin-hydrazone 2 could recognize the real amine during chicken meat spoilage from yellow to light brown after 24 h storage at room temperature.

Volumetric and spectroscopic properties of binary liquid mixtures of isopentyl alcohol with butylamine at T = (288.15–333.15) K

The current article presents the experimental density (ρ) values reported as a function of mole fraction for the binary liquid mixtures of isopentyl alcohol (IPA) + butylamine (BA) at the temperatures T = (288.15 to 333.15) K with 5 K intervals under atmospheric pressure (0.1 MPa). Based on experimental data, the molar volume (Vm), excess molar volume (VmE), apparent molar volumes (Vm,∅,1and Vm,∅,2), partial molar volumes (V-m,1and V-m,2), and excess partial molar volumes (V-m,1E and V-m,2E) values were computed over the complete mole fraction range. Also, at infinite dilution, the values of partial molar volumes (V¯m,1° and V¯m,2°), and excess partial molar volumes (V¯m,1°E and V¯m,2°E) of the isopentyl alcohol and butylamine were calculated. The calculated VmE values were correlated to the Redlich-Kister (R-K) model. Further, the excess molar volume was theoretically described by using Prigogine-Flory-Patterson (PFP) theory at the above temperatures. The obtained excess molar volume shows negative deviations from the ideal behaviour and becomes more negative at a higher temperature. From the above said parameters results, the H-bonding and acid-base interactions in the unlike molecules was determined. Additionally, the existence of new H-bonding interaction between IPA and BA molecules was further confirmed using 1H NMR and FT-IR spectroscopic studies.

Effect of amine length in the interference of the multipoint covalent immobilization of enzymes on glyoxyl agarose beads

Trypsin, chymotrypsin, penicillin G acylase and ficin extract have been stabilized by immobilization on glyoxyl agarose, adding different aliphatic compounds bearing a primary amine group during the immobilization: ethyl amine, butyl amine, hexyl amine (at concentrations ranging from 0 to 20 mM) and octyl amine (from 0 to 10 mM) to analyze their effects on the immobilized enzyme stability. As expected, the presence of amines reduced the intensity of the enzyme-support multipoint covalent attachment, and therefore the enzyme stability. However, it is clear that this effect is higher using octyl amine for all enzymes (in some cases the enzyme immobilized in the presence of 10 mM octyl amine was almost inactivated while the reference kept over 50 % of the initial activity). This way, it seems that the most important effect of the presence of aminated compounds came from the generation of steric hindrances to the enzyme/support multi-reaction promoted by the ammines that are interacting with the aldehyde groups. In some instances, just 1 mM of aminated compounds is enough to greatly decrease enzyme stability. The results suggested that, if the composition of the enzyme extract is unknown, to eliminate small aminated compounds may be necessary to maximize the enzyme-support reaction.

МОДИФИКАЦИЯ СОПОЛИМЕРОВ НА ОСНОВЕ ОЛЕФИНОВ И МАЛЕИНОВОГО АНГИДРИДА КАК PPD ДЛЯ ПАРАФИНИСТЫХ НЕФТЕЙ

In this work, we investigated a modification of a copolymer based on α-olefin (octadecene-1) (ODC) and maleic anhydride (MA) synthesized by the method of initiated radical polymerization. In the studies carried out, it was revealed that of all the synthesized copolymers based on maleic anhydride, the copolymer with α-octadecene was the most effective copolymer in reducing the viscosity of oil and TPT. In this work, a copolymer based on maleic anhydride and octadecene-1 (ODC – MA) was modified with primary amines – butylamine (BA), hexylamine (HA), hexadecylamine (HDA), octadecylamine (ODA), benzylamine (BzA). The copolymer was modified in a xylene solution with a Dean – Stark packing; the ratio of the ODC – MA copolymer to amines was 1:1.2 mol. Tololsulfonic acid (TSC) 0.5 wt% was used as a catalyst. Synthesis temperature 140°C, time 8 hours. The degree of completion of the reaction was evaluated by the amount of water formed in the Dean Stark packing. Modified copolymers ODC – MA with amines (ODC – MA – BA, ODC – MA – HA, ODC – MA – HDA, ODC – MA – ODA, ODC – MA – BzA) were characterized by Fourier IR spectroscopy and 1H and 13C NMR spectroscopy, which indicates the transformation of the original anhydride rings into imide ones. Modified copolymers were tested on waxy oil as depressants. Moreover, all modified copolymers exhibit the properties of depressants – they reduce the viscosity and TPT of oil relative to oil without an PPD. The morphology of waxy crystals formed in oil during a decrease in temperature was determined by microscopy; it was shown that modified waxy crystals of small sizes are formed compared to the original oil without PPDs, which indicates the dispersing effect of modified copolymers based on ODC – MA.

Close-loop recycling of perovskite solar cells through dissolution-recrystallization of perovskite by butylamine

Organic-inorganic lead halide perovskite solar cells (PSCs) have achieved impressive progress in both conversion efficiency and stability. However, the leakage risk of toxic lead in the fabrication and service of PSCs hinders their commercialization; hence, the management of lead is imperative. Here, we report a close-loop recycling strategy to collect the key materials involved in devices with butylamine (BA), even regenerating solar cells with recycled materials including perovskite absorbers and NiOx-coated ITO glass substrates. The regenerated devices show performance equivalent to that of fresh ones and nearly 18% PCE for the champions. The total recycling yield of lead is more than 98.9%. The recycling can be attributed to the unique interaction between lead halides and BA. Our strategy could move PSCs toward commercialization by effective close-loop recycling and refabrication of whole PSC devices.

A conjugated ligand interfacial modifier for enhancing efficiency and operational stability of planar perovskite solar cells

SnO2 is a promising alternative for TiO2 electron transporting layer (ETL), owing to the high charge mobility and chemical stability. Defects accumulating at interfaces and grain boundaries are detrimental to the performance of perovskite solar cells (PSCs). Herein, a ligand-biphenyl-3,3′,5,5′-tetracarboxylic acid butyl amine (BPTC-BN) with four carbonyls and conjugated electron is used to passivate defects at SnO2/perovskite interface. Meanwhile perovskite grown on SnO2/BPTC-BN shows increased and uniform grain size. Benefitting from decreased defects at interface and bulk perovskite, a planar PSC with a power conversion efficiency (PCE) of 21.23% and an open voltage (VOC) of 1.164 V is obtained. In contrast, devices based on single SnO2 layers deliver a PCE of 19.38% and a VOC of 1.114 V. In addition, this interface passivation strategy also improves device operational stability substantially, retaining 84% of its initial efficiency after 1000 h tracking at maximum power point (MPP). The results prove the prime importance of interface for the photovoltaic performance especially operational stability of PSCs.

Interplay between Perovskite Magic-Sized Clusters and Amino Lead Halide Molecular Clusters.

Recent progress has been made on the synthesis and characterization of metal halide perovskite magic-sized clusters (PMSCs) with ABX3 composition (A = CH3NH3+ or Cs+, B = Pb2+, and X = Cl−, Br−, or I−). However, their mechanism of growth and structure is still not well understood. In our effort to understand their structure and growth, we discovered that a new species can be formed without the CH3NH3+ component, which we name as molecular clusters (MCs). Specifically, CH3NH3PbBr3 PMSCs, with a characteristic absorption peak at 424 nm, are synthesized using PbBr2 and CH3NH3Br as precursors and butylamine (BTYA) and valeric acid (VA) as ligands, while MCs, with an absorption peak at 402 nm, are synthesized using solely PbBr2 and BTYA, without CH3NH3Br. Interestingly, PMSCs are converted spontaneously overtime into MCs. An isosbestic point in their electronic absorption spectra indicates a direct interplay between the PMSCs and MCs. Therefore, we suggest that the MCs are precursors to the PMSCs. From spectroscopic and extended X-ray absorption fine structure (EXAFS) results, we propose some tentative structural models for the MCs. The discovery of the MCs is critical to understanding the growth of PMSCs as well as larger perovskite quantum dots (PQDs) or nanocrystals (PNCs).

Degradation of various thiol collectors in simulated and real mineral processing wastewater of sulfide ore in heterogeneous modified manganese slag/PMS system

Residual flotation reagents (FRs) in mineral processing wastewater (MPW) cause serious organic pollution and difficult to discharge or recycle of MPW. In this study, the degradation of 100 mg/L of FRs (butyl xanthate (BX), diethyl dithiocarbamate (DDTC), ester-200 (Z-200) and butyl amine (BA)) commonly used for metal sulfide ore flotation were investigated by heterogeneous advanced oxidation process (AOPs) adopting peroxymonosulfate (PMS) as oxidants and modified manganese slag as metal-base catalyst (MS-N3H). The results showed MS-N3H/PMS system had higher degradation capacity than other reports, by which 100% of DDTC and 97.3% of BX could be degraded in 10 min, also 93.2% of Z-200 and 85.6% of BA were degraded in 30 min, respectively. The differential behaviours in degradation of thiol collectors (TCs) were correlated to their molecule structures and affected by their HMO index. However, the good water solubility of BX made it as the most degradable reagents in competitive system. The catalytic reactions of Z-200 and BA were pH-dependent processes which were dominated by the PMS ionization and base activation. Inorganic ions had little effects on reactions except for SiO32−, but the negative effect could be alleviated by the integrated process. Higher mineralization degrees of C, S and N elements indicated that TCs and their by-products were removed by the MS-N3H/PMS with higher degradation rates. Further, the catalyst showed superior regeneration ability and the system could be effectively used in real MPW treatment with relatively high removal efficiency of total organic carbon (TOC).

The assembly of silica species with alkylamines: Mechanism of wastewater-free synthesis and the application of gel as a catalyst

Silica species generated by the hydrolysis and condensation of tetraethyl orthosilicate (TEOS) could assemble with alkylamines to form silica gel. Herein, it was evidenced that part of the added amines, including butylamine (BA), octylamine (OA) or dodecylamine (DA), was protonated in the mixture of water and ethanol. Therefore, besides the hydrogen bonding between neutral silica species and the micelles composed of the non-protonated amines (Tanev and Pinnavaia, 1995), there existed strong electrostatic attraction between negatively charged silica species and the micelles composed of the protonated amines. This coexisting assembly mechanism could explain why the uncalcined BA- and OA-gels were millimeter-sized small blocks with large porosities and synthesized without waste water emission, while the uncalcined DA-gel was almost non-porous and formed via precipitation from its reaction medium. The uncalcined BA gel was proved to be efficient as a solid basic catalyst, replacing the commonly used ammonia solution which is easily volatilized and has a pungent smell, for the hydrolysis and condensation of TEOS to prepare silica microspheres.

Ionic matrices for matrix-assisted laser desorption/ionization mass spectrometry analysis of microRNA biomarkers

The use of ionic matrices (IMs) was evaluated as an alternative to conventional matrices to analyze microRNAs (miRNAs) by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). 2, 4, 6-Trihydroxyacetophenone (THAP), 6-aza-2-thiothymine (ATT) and 3-hydroxypicolinic acid (3-HPA) and their IMs with pyridine (PYR) and butylamine (BA) were studied to analyze a standard mixture of miRNAs: miR-21, let-7g and iso-miR-16. Among all the studied matrices, ATT-PYR at 75 mg/mL in acetonitrile (MeCN):H2O (50:50, v/v) was selected as the optimal. Furthermore, addition of ammonium citrate dibasic (AC) as signal enhancer was mandatory to obtain an appropriate miRNA detection. ATT-PYR provided the best sensitivity, with limit of detection (LOD) up to 5 nM (equivalent to 1 fmol in the spot) and excellent spot-to-spot repeatability due to the improved homogeneity of the spots compared to the conventional matrices. The applicability of the established method to direct, multiplex and untargeted analysis of miRNAs in serum samples was also investigated.

Pullulan derivative with cationic and hydrophobic moieties as an appropriate macromolecule in the synthesis of nanoparticles for drug delivery

A new amphiphilic pullulan derivative (DBAP-PO) was obtained by grafting tertiary butyl amine and octanoyl groups on the pullulan backbone as cationic and hydrophobic moieties, respectively. The structural characteristics of the modified polymer were investigated by FT-IR and 1H and 13C NMR spectroscopy.The self-association ability in aqueous solution of DBAP-PO was studied by viscosity and fluorescence methods. The intrinsic viscosity of the polymer was determined by Wolf model. The critical aggregation concentration (CAC) value of 0.028 g/dL, determined by fluorescence measurements in the presence of pyrene, was confirmed by capillary viscosimetry and dynamic laser scattering (DLS). Dialysis method was used to demonstrate the capacity of the pullulan derivative to form spherical nanoparticles (d ~ 200 nm) loaded with model drug, sodium diclofenac (DF) (74% entrapment efficiency). The DF release was sustained and pH-dependent. In vitro cytotoxicity as well as morphological studies conducted on the human skin fibroblasts showed that DBAP-PO/DF nanoparticles do not exhibit cytotoxic effects at the pharmacologically relevant concentration of DF, maintaining the typical morphology of the cells.

Batch investigation on volumetric, acoustic and calorimetric properties for binary mixtures of aniline + (diethanolamine, triethanolamine, butylamine and hexylamine) from experimental and theoretical point of view

Density and speed of sound for binary systems of diethanolamine (DEA), triethanolamine (TEA), butylamine (BUT) and hexylamine (HEX) in aniline (ANL) were measured at temperature ranges of (303.15–318.15) K. From the measured experimental data, excess molar volume, VmE and deviation in isentropic compressibility, ∆kS were calculated. Excess molar enthalpy HmE was also calculated for the above mentioned systems at 303.15 K only. The values of VmE and HmE were negative for all systems in the whole composition range. The results were analyzed to discuss the effect of the alkyl chain length, the orientation and number of the OH groups and the structural deformation of the molecules in the face of unlike molecules. The values of VmE, ∆kS and HmE were correlated by Redlich ̶ Kister polynomial equation. The obtained values were used to evaluate the nature and type of intermolecular interaction in multicomponent mixtures. The experimental excess molar enthalpy data have been correlated with two thermodynamics models Wilson and NRTL. Theoretical calculations were also performed using the ab initio method to validate the data in which the associated molecular interactions were compared and discussed. The agreement between theoretical and experimental data was acceptable for all studied systems.

Studies on the interactional behaviour of binary liquid mixtures of tripropylene glycol monomethyl ether and butyl amines at different temperatures

In the present study densities, ρ, and speeds of sound u, have been measured for the binary mixtures of tripropylene glycol monomethyl ether with butyl amine, dibutyl amine, and tributyl amine across the entire composition range at temperatures T = (288.15, 293.15, 298.15, 303.15, 308.15) K and experimental pressure p = 0.1 MPa. Experimental densities and speeds of sound data has been used to determine excess molar volumes, isentropic compressibility, molar isentropic compressibility KS,m and its excess counterpart excess molar isentropic compressibility. Deviations in intermolecular free length and deviations in acoustic impedance have also been determined. Further we have also calculated the partial molar volumes for binary mixtures at different temperatures. The variation of these determined parameters with temperature and composition has been discussed with a view to understand molecular interactions present in the binary liquid mixtures of alkoxypropanol and butyl amines. The experimental data has also been fitted with Jouyban-Acree model.

Amine-passivated ZnO electron transport layer for thermal stability-enhanced perovskite solar cells

n-Type zinc oxide (ZnO) has high electron mobility, good light transmittance, and a suitable work function and is considered to be a suitable electron transport material in perovskite solar cells (PSCs). However, the chemical compatibility between ZnO and perovskites is poor, making it difficult to prepare highly efficient and stable PSCs by a one-step spin coating method. Here, the ZnO surface is modified with three amino compounds, butylamine (BA), isobutylamine (IBA) and 2-amino-2-methyl-1-propanol (AMP). Three amino compounds can react with 3D perovskite to form a thin and more stable perovskite with a 2D structure, which can improve the stability of ZnO-based PSCs fabricated by one-step method. Interestingly, the conductivity of amine-modified ZnO is also improved due to the presence of amino (NH2) and hydroxyl (OH) groups which can induce the dipole polarization. The modification of amino compounds on the surface of ZnO can affect the hydrophilicity of ZnO surface that is related to the crystallization of perovskite film. Devices with IBA modification exhibit improved stability, and the power conversion efficiency (PCE) can reach 18.84%. Therefore, we provide a new strategy to improve the surface of the ZnO electron transport layer for high-performance PSCs fabricated by a one-step method.

Branched Alkylamine-Reduced Graphene Oxide Hybrids as a Dual Proton-Electron Conductor and Organic-Only Water-Splitting Photocatalyst.

We report multifunctionalities including the solid electrolytic property, electron conductivity (EnC), and photocatalytic water splitting (PWS) ability of organic-only hybrids obtained by intercalating short and branched-chain alkylamines including methylamine (MA), butylamine (BA), pentylamine (PA), and isomethylbytylamine (IMBA) in reduced graphene oxide (rGO). The alkylamine-rGO hybrids were synthesized by a facile solid-state reduction process. Within the series, IMBA-rGO exhibited high proton conductivity (PrC), EnC, and optimized PWS capacity. The PrC of IMBA-rGO was from 10-4 to 10-3 S cm-1, which is only half an order less than that for pristine GO. The EnC was 1.25 μA/V. Though the PWS performances of MA-rGO, BA-rGO, and PA-rGO were comparatively lower, IMBA-rGO could generate about 1.5 times H2 compared with that for R-TiO2. The IR spectra indicate the association of IMBA and GO by chemical bonds. The Raman spectra show the transformation of GO's nonconductive sp3 carbon sites into electron-conductive sp2 carbon centers. The thermogravimetric analysis show improved water adsorbing capacity of IMBA-rGO, which resulted in higher PrC. Doping of the nitrogen atom at the graphitic sp2 system was confirmed from the presence of pyrrolic N in X-ray photoelectron spectroscopy spectra. The resultant N-type semiconducting behavior is majorly responsible for the PWS process. The powder X-ray diffraction analysis indicates a more flexible interlayer space in IMBA-rGO, which facilitates both the reformation of hydrogen bonds during proton conduction and water dynamics during photocatalysis. The material indicates the possibility of devising graphene-based organic-only multifunctional hybrids.

Spatial and temporal distribution characteristics and ozone formation potentials of volatile organic compounds from three typical functional areas in China

BackgroundOzone is currently one of the most important air pollutants. Volatile organic compounds (VOCs) can easily react with atmospheric radicals to form ozone. In-field measurement of VOCs may help in estimating the local VOC photochemical pollution level. MethodThis study examined the spatial and temporal distribution characteristics of VOCs during winter at three typical sites of varying classification in China; industrial (Guangzhou Economic and Technological Development District (GETDD)), urban (Guangzhou higher education mega center (HEMC)), and rural (Pingyuan county (PYC)), using Proton-Transfer-Reaction Time-of-Flight Mass Spectrometry (PTR-ToF-MS). ResultsThe concentrations of total VOCs (TVOCs) at the GETDD, HEMC and PYC sites were 352.5, 129.2 and 75.1 ppb, respectively. The dominant category of VOCs is nitrogen-containing VOCs (NVOCs, accounting for 43.3% of TVOCs) at GETDD, of which C4H11N (m/z+ = 74.10, butyl amine) was the predominant chemical species (80.5%). In contrast, oxygenated VOCs (OVOCs) were the most abundant at HEMC and PYC, accounting for 60.2% and 64.1% of the total VOCs, respectively; here, CH4O (m/z+ = 33.026, methanol) was the major compound, accounting for 40.5% of the VOCs at HEMC and 50.9% at PYC. The ratios of toluene to benzene (T/B) were calculated for different measured sites, as the ratios of T/B can reveal source resolution of aromatic VOCs. The average contributions to total ozone formation potentials (OFP) of the total measured VOCs in each area were 604.9, 315.9 and 111.7 μg/m3 at GETDD, HEMC and PYC, respectively; the highest OFP contributors of the identified VOCs were aliphatic hydrocarbons (AlHs) at GETDD, aromatic hydrocarbons (AHs) at HEMC, and OVOCs at PYC. ConclusionsOFP assessment indicated that the photochemical pollution caused by VOCs at GETDD was serious, and was also significant in the HEMC region. The dominant VOC OFP groups (AlHs and AHs) should be prioritized for control, in order to help reduce these effects.

Hydrotropy: A Boon in Thin layer Chromatography A Review

Around a century ago, in 1916, the term ‘hydrotropy’ was coined by the scientist Carl A. Neuberg to concentrate on anionic organic salts which significantly enhanced the aqueous solubility of weakly soluble solutes1. The thin layer chromatography (TLC) of drugs are usually performed with the help of solvents like butyl amine, toluene, ether, chloroform, light petroleum, ethyl acetate, ethanol, hexane, xylene and phenol. The majority of which are much expensive and toxic1-3. Now a days, aqueous solubility of drugs is major problem in pharmaceutical field. Hydrotropic agents are employed as mobile phase for estimation of poorly aqueous soluble drugs by TLC technique. The current review takes the readers throughout a brief summary, geometrical Features of hydrotropic agents, and their different advances toward Chromatographic techniques. Moreover, this review would provide an insight of the future perspectives concerned with the TLC and hydrotropism. In future, hydrotropic solutions shall prove a boon in TLC and high performance thin layer chromatography (HPTLC) analysis of a vast number of drugs thereby limiting the use of organic solvents to a great extent.