scholarly journals A method for measuring total aerosol oxidative potential (OP) with the dithiothreitol (DTT) assay and comparisons between an urban and roadside site of water-soluble and total OP

2017 ◽  
Author(s):  
Dong Gao ◽  
Ting Fang ◽  
Vishal Verma ◽  
Linghan Zeng ◽  
Rodney Weber
Keyword(s):  
Organic Solvents ◽  
Coefficient Of Variation ◽  
Extraction Method ◽  
Pure Water ◽  
Water Soluble ◽  
Aerodynamic Diameter ◽  
Oxidative Potential ◽  
The Third ◽  
Analytical System ◽  
Solid Aerosol

Abstract. An automated analytical system was developed for measuring the oxidative potential (OP) with the dithiothreitol (DTT) assay of filter extracts that include both water-soluble and water-insoluble (solid) aerosol species. Three approaches for measuring total oxidative potential were compared. These include using methanol as the solvent with (1) and without (2) filtering the extract, followed by removing the solvent and reconstituting with water, and (3) extraction in pure water and performing the OP analysis in the extraction vial with the filter. The water extraction method (the third approach, with filter remaining in the vial) generally yielded highest DTT responses with better precision (coefficient of variation of 1–5 %), and was correlated with a greater number of other aerosol components. Because no organic solvents were used, which must be mostly eliminated prior to DTT analysis, it was the easiest to automate by modifying an automated analytical system for measuring water-soluble OP developed by Fang et al. (2015). Daily 23h filter samples were collected simultaneously at a roadside (RS) and a representative urban (GT) site for two one-month study periods, and both water-soluble (OPWS-DTT) and total (OPTotal-DTT) OP were measured. Using PM2.5 (aerodynamic diameter

scholarly journals A method for measuring total aerosol oxidative potential (OP) with the dithiothreitol (DTT) assay and comparisons between an urban and roadside site of water-soluble and total OP

2017 ◽  
Vol 10 (8) ◽  
pp. 2821-2835 ◽  
Author(s):  
Dong Gao ◽  
Ting Fang ◽  
Vishal Verma ◽  
Linghan Zeng ◽  
Rodney J. Weber
Keyword(s):  
Pure Water ◽  
High Volume ◽  
Water Soluble ◽  
Urban Site ◽  
Georgia Tech ◽  
Oxidative Potential ◽  
The Third ◽  
Analytical System ◽  
Solid Aerosol

Abstract. An automated analytical system was developed for measuring the oxidative potential (OP) with the dithiothreitol (DTT) assay of filter extracts that include both water-soluble and water-insoluble (solid) aerosol species. Three approaches for measuring total oxidative potential were compared. These include using methanol as the solvent with (1) and without (2) filtering the extract, followed by removing the solvent and reconstituting with water, and (3) extraction in pure water and performing the OP analysis in the extraction vial with the filter. The water extraction method (the third approach, with filter remaining in the vial) generally yielded the highest DTT responses with better precision (coefficient of variation of 1–5 %) and was correlated with a greater number of other aerosol components. Because no organic solvents were used, which must be mostly eliminated prior to DTT analysis, it was easiest to automate by modifying an automated analytical system for measuring water-soluble OP developed by Fang et al. (2015). Therefore, the third method was applied to the field study for the determination of total OP. Daily 23 h filter samples were collected simultaneously at a roadside (RS) and a representative urban (Georgia Tech, GT) site for two 1-month study periods, and both water-soluble (OPWS-DTT) and total (OPTotal-DTT) OP were measured. Using PM2. 5 (aerodynamic diameter  <  2.5 µm) high-volume samplers with quartz filters, the OPWS-DTT-to-OPTotal-DTT ratio at the urban site was 65 % with a correlation coefficient (r) of 0.71 (N  =  35; p value  <  0.01), compared to a ratio of 62 % and r = 0. 56 (N  =  31; p value  <  0.01) at the roadside site. The same DTT analyses were performed, and similar results were found using particle composition monitors (flow rate of 16.7 L min−1) with Teflon filters. Comparison of measurements between sites showed only slightly higher levels of both OPWS-DTT and OPTotal-DTT at the RS site, indicating both OPWS-DTT and OPTotal-DTT were largely spatially homogeneous. These results are consistent with roadway emissions as sources of DTT-quantified PM2. 5 OP and indicate that both soluble and insoluble aerosol components contributing to OP are largely secondary.

scholarly journals Eco-friendly and Economical Spectrophotometric Estimation of the Low Water-Soluble Drug (Norfloxacin) Applying the Concept of Mixed Hydrotropy

2021 ◽  
Author(s):  
Ketan Soni ◽  
Kavita Sharma
Keyword(s):  
Standard Deviation ◽  
Organic Solvents ◽  
Standard Error ◽  
Coefficient Of Variation ◽  
Dosage Forms ◽  
Water Soluble ◽  
Current Analysis ◽  
Water Soluble Drug ◽  
Water Soluble Drugs ◽  
Bulk Drug

Abstract Objectives The main aim of the research was to analyze an economical and eco-friendly approach to improve the solubility of norfloxacin. The current analysis was to utilize the hydrotropic solutions to extract the drugs from their dosage forms, avoiding the use of costlier and harmful organic solvents. Materials and Methods In this study, an ultraviolet–visible spectrophotometer (model 1800, Shimadzu Corporation) was used to analyze the norfloxacin drug. The mixed hydrotropy approach was used to determine the solubility of norfloxacin. In this work, a blend solution (20% of urea + 20% of sodium benzoate) was used as a hydrotropic solubilizing agent. Results The solubility of norfloxacin drug in water was very low at ∼0.88 mg/mL and the solubility of norfloxacin drug in the blend solution was 11 mg/mL. From 98.96 (tablet II) to 99.35 (tablet I), the percent estimation value was achieved. This value was nearly 100, so the proposed method was correct. Standard deviation (0.2540–0.4156), percentage coefficient of variation (0.2566–0.4183), and the value of standard error (0.1481–0.2415) are also very low; hence, we can say that the proposed method is accurate. Conclusion To avoid the use of organic solvents, the mixed hydrotropy concept can be used for spectrophotometric estimation of low water-soluble drugs from bulk drug samples. It provides an economical and environmentally friendly mechanism.

Synthesis and Photoproperties of a Substituted Zinc(II) Phthalocyanine-N-(2-hydroxypropyl)methacrylamide Copolymer Conjugate

1993 ◽  
Vol 58 (10) ◽  
pp. 2321-2336 ◽  
Author(s):  
Zhong-wei Gu ◽  
John D. Spikes ◽  
Pavla Kopečková ◽  
Jindřich Kopeček
Keyword(s):  
Organic Solvents ◽  
Water Soluble ◽  
Lower Probability ◽  
Hpma Copolymer ◽  
Polymeric Derivative ◽  
Oxygen Generation ◽  
Hpma Copolymers ◽  
Hydroxypropyl Methacrylamide ◽  
Polymeric Carriers ◽  
Thiol Proteinases

In cancer photodynamic therapy (PDT), improved efficiency of photosensitizer delivery to tumors may be obtained by binding them to targetable water soluble polymeric carriers. However, attachment of photosensitizers to Macromolecular carriers may alter their spectral and photosensitizing properties. In this study, a new monosubstituted phthalocyanine derivative, N-glycyl zinc(II) 4,9,16,23-tetraaminophthalocyanine (G-TAPC-Zn) was synthesized by the reaction of zinc(II) 4,9,16,23-tetraaminophthalocyanine (TAPC-Zn) with N-tert-butoxycarbonyl-glycine N'-hydroxybenzotriazole ester followed by deprotection of the tert-butoxycarbonyl (BOC) group. G-TAPC-Zn contains an aliphatic amino group suitable for attachment to water soluble polymeric carriers. By aminolysis of a polymeric precursor, an N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer containing oligopeptide (GFLG) side-chains terminated in p-nitrophenyl ester groups, with G-TAPC-Zn a polymeric derivative of the latter (P-GFLGG-TAPC-Zn) was synthesized. Spectral data indicated that in aqueous solutions P-GFLGG-TAPC-Zn formed aggregates. The degree of aggregation decreased with increasing concentration of detergents or organic solvents in buffer solutions. Consequently, the release of the drug from carrier catalyzed by thiol proteinases, papain or cathepsin B, took place only in the presence of detergents or organic solvents, i.e., under conditions with a lower probability of aggregate formation. Binding of G-TAPC-Zn to HPMA copolymers decreased the quantum yield of singlet oxygen generation from 0.24 to 0.063 and significantly increased its resistance to photobleaching.

Study on Pure Aqueous Extraction Method of PHB/Ectoine Co-Products Based on Osmotic Downshock

2014 ◽  
Vol 955-959 ◽  
pp. 3377-3380 ◽  
Author(s):  
Qing Chen ◽  
Te Wang ◽  
Jin Dan Zhao ◽  
Fu Hui Kang ◽  
Yi Ming Zhang ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Hollow Fiber ◽  
Extraction Method ◽  
Pure Water ◽  
Aqueous Extraction ◽  
Extraction Rate ◽  
Extraction Temperature ◽  
Optimal Conditions ◽  
Pressure Extraction ◽  
Osmotic Downshock

The simultaneously co-production of Poly-β-hydroxybutyrate (PHB) and ectoine in a process (PHB/Ect co-production) and co-products extraction have great significant for reducing the manufacture cost and promoting industrialization of PHB and ectoine. The pure aqueous extraction method based on osmotic downshock was used for the extraction of PHB/Ect co-products byH. salina. The effects of osmotic pressure, extraction temperature and extraction time on the extraction rate of PHB were investigated. The ectoine was extracted and purified by the techniques of hollow fiber and ion exchange. The optimal conditions for PHB extraction were osmotic downshock in pure water, extraction temperature at 60 °C and extraction for 4 h. The extraction rate of PHB was 87.5%. The extraction rate of ectoine was 84.2%.

scholarly journals Water Soluble Pleurotus ostreatus Polysaccharide Down-Regulates the Expression of MMP-2 and MMP-9 in Caco-2 Cells

2013 ◽  
Vol 41 (2) ◽  
pp. 553
Author(s):  
Sabina COJOCARU ◽  
Mihaela RADU ◽  
Liviu Gabriel BODEA ◽  
Mirela Mihaela CIMPEANU ◽  
Gogu GHEORGHITA ◽  
...  
Keyword(s):  
Colon Cancer ◽  
Cancer Cells ◽  
Protein Complexes ◽  
Gelatin Zymography ◽  
Water Soluble ◽  
Colon Cancer Cells ◽  
Sod Activity ◽  
Kinetic Measurements ◽  
The Third

Many polysaccharides and polysaccharide-protein complexes isolated from mushrooms have immunomodulatory and anti-cancer effects. Our aim was to study the regulatory mechanisms of Caco-2 cell response to water soluble P. ostreatus polysaccharide extract up to 72 hours. Specific enzymatic activities were assessed by kinetic measurements. The reduced glutathione content and the lipid peroxidation level were also analyzed. Protein expression of several heat shock proteins, Bcl-2 and metalloproteinases 2 and 9 were revealed by Western blot. Gelatin zymography assay was used to evaluate the MMP-2 and MMP-9 activities. Until the third day of exposure the total SOD activity decreased continuously by 30%, whereas GST and GR ones diminished by 17% respectively 30.5% compared to control. No significant changes were observed in CAT and G6PDH specific activities as well as in GSH and MDA concentration. After the third day of exposure a significant up-regulation of Hsp60 and Hsp90 expression and a down-regulation of Hsp70 one were registered. Bcl-2 protein levels were down-regulated by 50% in the first day of treatment but increased after 3 days. MMP-2 and 9 secretion in the culture medium was significantly reduced suggesting a diminished ability of invasion of colon cancer cells. Our data revealed that in vitro treatment with P. ostreatus aqueous polysaccharide extract does not induce apoptosis in Caco-2 cell line but it could inhibit the invasion of colon cancer cells through the basement membrane.

scholarly journals EXTRACTION METHODS OF CLEANING OF MOTOR FUEL

2019 ◽  
Vol 62 (10) ◽  
pp. 30-39
Author(s):  
Sabina A. Seidova
Keyword(s):  
Organic Solvents ◽  
Extraction Method ◽  
Motor Fuel ◽  
Extraction Methods ◽  
National Academy Of Sciences ◽  
Selective Solvent ◽  
High Quality ◽  
Motor Fuels ◽  
Temperature And Pressure ◽  
Academy Of Sciences

In paper the results of the carried out analysis of literary data on preparation of motor fuels of high quality by extraction method of purification of the corresponding oil distillates with use of compounds of various class as a selective solvent have been presented. In particular, the results of comparative analysis of existing methods of the extraction purification of distillates of motor fuels from unnecessary components – aromatic hydrocarbons, sulphur-containing compounds and resinous substances with use of organic solvents and ion-liquid compositions as a selective solvent have been presented. The advantage of the extraction method of purification of motor fuels determined by possibility of the process at low temperature and pressure, by absence of necessity of application of the expensive catalysts, by possibility of regeneration and reuse of solvent, etc. in comparison with widely used hydrogenation method has been shown. The lacks of the organic solvents used as an extractant have been also listed and due to the ecological problems the use of non-volatile, thermally stable ion-liquid compositions as a selective solvent in the processes of purification of the distillates, intended for preparation a high quality target products, such as diesel fuel, gasoline, base oils for various purposes has been substantiated. In paper the results of systematic investigations carried out at the Institute of Petrochemical Processes of Azerbaijan National Academy of Sciences with the participation of the authors themselves, concerning the selective purification of the oil fractions of various composition and viscosity with use of ionic liquids synthesized on the basis of formic and acetic acids composition have been also presented. By carried out analysis it has been shown the perspectivity of application of the ion-liquid compositions as an extractant in the processes of the selective purification of the oil distillates.

scholarly journals Photo-transformation of aqueous nitroguanidine and 3-nitro-1,2,4-triazol-5-one : emerging munitions compounds

2021 ◽  
Author(s):  
Julie Becher ◽  
Samuel Beal ◽  
Susan Taylor ◽  
Katerina Dontsova ◽  
Dean Wilcox
Keyword(s):  
Aqueous Solutions ◽  
Degradation Products ◽  
Pure Water ◽  
Transformation Products ◽  
Water Soluble ◽  
Uv Exposure ◽  
Degradation Pathways ◽  
Solution Ph ◽  
Photo Degradation ◽  
Degradation Rates

Two major components of insensitive munition formulations, nitroguanidine (NQ) and 3-nitro-1,2,4-triazol-5-one (NTO), are highly water soluble and therefore likely to photo-transform while in solution in the environment. The ecotoxicities of NQ and NTO solutions are known to increase with UV exposure, but a detailed accounting of aqueous degradation rates, products, and pathways under different exposure wavelengths is currently lacking. We irradiated aqueous solutions of NQ and NTO over a 32-h period at three ultraviolet wavelengths and analyzed their degradation rates and transformation products. NQ was completely degraded by 30 min at 254 nm and by 4 h at 300 nm, but it was only 10% degraded after 32 h at 350 nm. Mass recoveries of NQ and its transformation products were >80% for all three wavelengths. NTO degradation was greatest at 300 nm with 3% remaining after 32 h, followed by 254 nm (7% remaining) and 350 nm (20% remaining). Mass recoveries of NTO and its transformation products were high for the first 8 h but decreased to 22–48% by 32 h. Environmental half-lives of NQ and NTO in pure water were estimated as 4 and 6 days, respectively. We propose photo-degradation pathways for NQ and NTO supported by observed and quantified degradation products and changes in solution pH.

Impurities in Commercial Saccharin. I. Impurities Soluble in Organic Solvents

1976 ◽  
Vol 59 (5) ◽  
pp. 1051-1058 ◽  
Author(s):  
Bozidar Stavrić ◽  
Raymond Klassen ◽  
W Arnold
Keyword(s):  
Organic Solvents ◽  
Water Solution ◽  
Water Soluble ◽  
Chromatographic Column ◽  
Gas Liquid Chromatography ◽  
Sodium Saccharin ◽  
Chemical Purity ◽  
Liquid Chromatographic ◽  
Chloroform Methanol ◽  
Sodium Form

Abstract Thirteen saccharin samples used for carcinogenicity tests in animals in various laboratories were analyzed for their chemical purity. Although most of the impurities were water-soluble, some were mainly soluble in organic solvents. These impurities were extracted with chloroform-methanol from a water solution of sodium saccharin. Samples obtained as acid-saccharin were converted to the sodium form before extraction. The major impurity in commercial saccharin, o-toluenesulfonamide, was also soluble in this system. Impurities were separated by gas-liquid chromatography of the underivatized, concentrated extract. Eleven major, well separated peaks were collected from the gas chromatographic column and identified by mass spectroscopy. Some of the peaks were compared with known standards. Qualitative and quantitative differences in impurities were observed among different saccharin samples. The identified impurities (in order of appearance from the gas-liquid chromatographic column) were as follows: o-toluenesulfonamide; p-toluenesufonamide; 1,2-benzisothiazole 1,1-dioxide; 1,2-benzisothiazoline 1,1-dioxide; diphenylsulfone; o,o′-ditolylsulfone; o,m′-ditolylsulfone, o,p′-ditolylsulfone; m,p′-ditolylsulfone; p,p′-ditolylsulfone, and tetracosane.

scholarly journals Application of a Sequential Extraction Method for Analyzing Cu Distribution in Pre-Treated Mine Tailings after Electrodialytic Remediation

2019 ◽  
Vol 16 (4) ◽  
pp. 584 ◽  
Author(s):  
Andrea Lazo ◽  
Henrik Hansen ◽  
Pamela Lazo ◽  
Claudia Gutiérrez
Keyword(s):  
Sequential Extraction ◽  
Mine Tailings ◽  
Extraction Method ◽  
Constant Electric Field ◽  
Extraction Procedure ◽  
Water Soluble ◽  
Copper Compounds ◽  
Leaching Solution ◽  
Sequential Extraction Method ◽  
Pre Treatment

Mine tailings have been analyzed by a sequential extraction procedure after their pre-treatment with a leaching solution for 24 h and electrodialytic remediation during 15 days with a constant electric field of 2.7 V cm−1. Four leaching solutions were tested: H2SO4 + HNO3 (2:1 vol.) pH = 1.9; H2SO4 + HNO3 (2:1 vol) pH = 4.2; NH4Cl 0.8M, pH = 5.5 and 30% H2O2 adjusted to pH 2 with HNO3 1M + HCl 1M. After the treatment, the tailings were divided in six slices from anode to cathode. The highest removal efficiency of copper was obtained with H2SO4 + HNO3 pH = 1.9, which allows one to remove 67% of the copper in the total cell and 85% of the copper in the slice closest to anode. The same solution with pH = 4.2 allows one to remove 62% of the total copper. The analysis realized by the sequential extraction method indicates the easy removal of water-soluble and exchangeable fractions in all experiments, moreover, residual and sulfide are the less mobile fractions. The general trend was the movement of copper associated to different fractions from anode to cathode and its accumulation closest to the cathode in the case of exchangeable, Fe-Mn oxides and acid soluble fractions, possibly due to some precipitation of copper compounds associated with less acidic conditions.

scholarly journals Cyclopentadienone Iron Tricarbonyl Complexes-Catalyzed Hydrogen Transfer in Water

Molecules ◽  
2020 ◽  
Vol 25 (2) ◽  
pp. 421 ◽  
Author(s):  
Daouda Ndiaye ◽  
Sébastien Coufourier ◽  
Mbaye Diagne Mbaye ◽  
Sylvain Gaillard ◽  
Jean-Luc Renaud
Keyword(s):  
Metal Complexes ◽  
Hydrogen Transfer ◽  
Low Cost ◽  
Pure Water ◽  
Free Water ◽  
Water Soluble ◽  
Tricarbonyl Complex ◽  
Reaction Conditions ◽  
Catalytic Systems ◽  
Iron Tricarbonyl

The development of efficient and low-cost catalytic systems is important for the replacement of robust noble metal complexes. The synthesis and application of a stable, phosphine-free, water-soluble cyclopentadienone iron tricarbonyl complex in the reduction of polarized double bonds in pure water is reported. In the presence of cationic bifunctional iron complexes, a variety of alcohols and amines were prepared in good yields under mild reaction conditions.

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