Thermodynamic Models: Application to the Brines of Chotts in Algerian North-Eastern Sahara

The Brines of chotts in Algerian Northeastern Sahara are highly concentrated solutions of mineral salts with a salinity that far exceeds that of the sea water (120 to 440 g/l).

The first interpretation of data allows to specify the chemical facies of these brines form their chemical compositions. They have mainly a very marked sodic chlorinated character.

Databases of the thermodynamic model PHREEQC v3 were used to determine the saturated state of the brines with respect to principal chemical species. They are more oversaturated with calcite than with gypsum.

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Development and Application of Liquid Chromatography in Life Sciences

Liquid chromatographic approaches cover a wide range of applications today. It is closely relevant in scientific studies, which provides a powerful identification of certain components that will be effective for curing specificdiseases.

Liquid Chromatography

Especially important, LC methods can assist us for isolation and purification of therapeutic drugs that benefit for the development of medical industry. As the development of liquid chromatography, the single effective component within a drug can be separated and purified under extreme purity requirements from a biological system with great complexity and abundance. However, improvement of LC methods is still urgently needed for better application of this method to benefit our lives.

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Study of the Selectivity of Methane over Carbon Dioxide Using Composite Inorganic Membranes for Natural Gas Processing

Natural gas is an important fuel gas that can be used as a power generation fuel and as a basic raw material in petrochemical industries.

Its composition varies extensively from one gas field to another. Despite this variation in the composition from source to source, the major component of natural gas is methane with inert gases and carbon dioxide.

Hence, all natural gas must undergo some treatment with about 20% of total reserves requiring extensive treatment before transportation via pipelines.

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Silica Supported Heteropoly Catalysts for Oxidation of Methacrolein to Methacrylic Acid

The Cu2+ or Fe3+ substituted Cs2HPMo12O40 was synthesized to study the effect of transitional metal cations on selective catalytic oxidation of methacrolein by polyoxometalates.

Adding of Cu2+ could reduce acidity and enhance oxidizing ability of the catalyst. The catalytic experiments showed that the addition small amount of Cu2+ to the catalyst could increase the conversion of methacrolein from 65% to 96% and the selectivity to methacrylic acid to 55%, at 300-340°C.

It is found adding of Cu2+ could promote the reduction process of catalysts should be the main reason of the performance enhancement.

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Silica Supported Heteropoly Catalysts for Oxidation of Methacrolein to Methacrylic Acid

The Cu2+ or Fe3+ substituted Cs2HPMo12O40 was synthesized to study the effect of transitional metal cations on selective catalytic oxidation of methacrolein by polyoxometalates.

Adding of Cu2+ could reduce acidity and enhance oxidizing ability of the catalyst. The catalytic experiments showed that the addition small amount of Cu2+ to the catalyst could increase the conversion of methacrolein from 65% to 96% and the selectivity to methacrylic acid to 55%, at 300-340°C.

It is found adding of Cu2+ could promote the reduction process of catalysts should be the main reason of the performance enhancement. Adding of Fe3+ to the catalyst could induce some new weak acidic sites due to the formation of iron aqua complexes.

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N-Doped TiO2: An Efficient Catalyst for the Photocatalytic Treatment of Water and Wastewater under Visible Light Irradiation

As a consequence of the rapid growth of population in urban areas, water use and reuse has become a major concern, leading to an urgent imperative to develop effective and affordable technologies for wastewater treatment.

Traditional methods for wastewater treatment are usually based on physical and biological processes but unfortunately, some organic pollutants, classified as bio-recalcitrant, are not biodegradable.

In this way heterogeneous photocatalysis may become an interesting water treatment technology to remove organic pollutants not treatable by conventional technique.

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Qualitative and Quantitative Analysis of Dan-Deng-Tong-Nao Capsules by HPLC-DAD-MS/MS

Dan-Deng-Tong-Nao capsules (DDTNCs), a traditional Chinese medicinal preparation consisting of Radix Salvia miltiorrhiza, Radix Pueraria lobata, Erigeron breviscapus, Rhizoma chuanxiong has been used for the treatment of apoplexy and the syndrome of apoplexy involving both collaterals and meridians caused by obstruction of collaterals by blood stasis in China.

In this paper, a HPLC-DAD-MS/MS method was successfully developed for qualitative and quantitative analysis of major components in DDTNCs for the first time.

Twenty-six compounds were identified by comparison of their retention times and MS spectra with those elucidated standards or recorded literatures, and six of them (danshensu, 5-hydroxymethylfurfural, 3,4-dihydroxybenzaldehyde, epicatechin, puerarin and salvianolic acid A) were simultaneously determined by HPLC-DAD quantitatively.

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Variable Electrospray Ionization and Matrix-Assisted Laser Desorption/ Ionization Mass Spectra of the Bisquaternary Ammonium Salt Ethonium

Determination of a single “fingerprint” mass spectrum of a biologically active compound, required for compound identification in mixtures and biological materials in such applied tasks as ecological monitoring and biological imaging, may become a nontrivial problem for labile compounds whose mass spectra depend strongly on the applied experimental conditions.

In the present communication, qualitatively different mass spectral patterns obtained for the bisquaternary ammonium salt ethonium Cat2+•2Cl– under varied conditions of electrospray ionization and matrixassisted laser desorption/ionization (MALDI) are described and systematized.

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Evaluation and Characterisation of Composite Mesoporous Membrane for Lactic Acid and Ethanol Esterification

Recently, the use of inorganic composite mesoporous membranes in chemical industries has received a lot of attention due to a number of exceptional advantages including thermal stability and robustness.

Inorganic mesoporous membranes can selectively remove water from the reaction product during lactic esterification reactions in order to enhance product yield.

In this work, the characterization and evaluation of a catalytic mesoporous membrane with 15 nm pore size was tested with different carrier gases before employing the gases for lactic acid and ethanol esterification product analysis with Gas Chromatography coupled with mass spectrometry

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Variable Electrospray Ionization and Matrix-Assisted Laser Desorption/ Ionization Mass Spectra of the Bisquaternary Ammonium Salt Ethonium

Determination of a single “fingerprint” mass spectrum of a biologically active compound, required for compound identification in mixtures and biological materials in such applied tasks as ecological monitoring and biological imaging, may become a nontrivial problem for labile compounds whose mass spectra depend strongly on the applied experimental conditions.

In the present communication, qualitatively different mass spectral patterns obtained for the bisquaternary ammonium salt ethonium Cat2+•2Cl– under varied conditions of electrospray ionization and matrixassisted laser desorption/ionization (MALDI) are described and systematized.

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Isotopic Abundance Analysis of Biofield Treated Benzene, Toluene and p-Xylene Using Gas Chromatography-Mass Spectrometry (GC-MS)

Benzene, toluene and p-xylene are derivatives of benzene, generally produced from crude petroleum and have numerous applications in industry.

The aim of the present study was to evaluate the impact of biofield treatment on isotopic abundance of these benzene derivatives by gas chromatography-mass spectrometry (GC-MS).

Benzene, toluene and p-xylene samples were divided into two parts: control and treatment. Control part was remained as untreated and treatment part was subjected to Mr. Trivedi’s biofield treatment.

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Arrested Precipitation Technique for Synthesis of Chalcogenide and Oxide Thin Films

Interest in the use of photo electrochemical solar cells for low cost energy conversion has led to an extensive research in the search for novel and suitable thin film semiconductor materials. The techniques presently used for synthesis of mixed metal chalcogenide and oxide thin films are CBD, MOCVD, spin coating, electro deposition, spray pyrolysis, sputtering, crystal growth, and chemical bath deposition.

All these deposition techniques require specific sophisticated instrumentation. In this regard APT is more attractive and relatively inexpensive presently used by us for deposition of mixed metal chalcogenide and oxide thin thin films.

In the present investigation we attempt to prepare mixed metal chalcogenide and oxide thin films by arrested precipitation technique. The purpose of work is to establish and optimize the growth condition to produce these thin films.

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Deoxygenation of Palmitic Acid to Produce Diesel-like Hydrocarbons over Nickel Incorporated Cellular Foam Catalyst

Nickel incorporated mesostructured cellular foam (NiMCF) was studied as a catalyst for palmitic acid deoxygenation to primarily synthesize n-pentadecane and 1-pentadecene. The kinetic behaviour was tested in a temperature range from 280 to 300°C.

The reaction was found to follow a first order kinetic model with respect to the palmitic acid with an activation energy of 111.57 KJ/Mol. In the reusability study, it was found that the average reduction in palmitic acid conversions was about 40.5%, which indicated the occurrence of catalyst deactivation during the deoxygenation. Fresh and spent catalysts were characterized by means of scanning electron microscope.

Energy-dispersive X-ray spectroscopy and X-ray powder diffraction correlate their characteristics with catalytic activity and to identify the main catalyst deactivation mechanism. The catalyst deactivation was mainly due to phase transformation of metallic nickel (Ni0) to nickel ion (Ni2+) and the deposition of organic molecules on the catalyst during the deoxygenation.

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Increased Enzyme Flexibility Doesnot Necessarily Lead to Substrate Promiscuity

Understanding the molecular basis of substrate promiscuity shown by some enzymes has been quite elusive. Enzymes that catalyze modification of aminoglycoside antibiotics show a wide range of substrate promiscuity.

Comparisons based on amino acid sequence similarity have been more confusing than leading to any explanations.

For example, several aminoglycoside modifying enzymes that catalyze different reactions and have less than 5% sequence identity and less than 12% sequence similarity show high overlap in their substrate profiles while some others despite catalyzing the same reaction and having >50% sequence similarity can have significant differences in their substrate profiles

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Gas Chromatographic Assessment of Residual Solvents Present in Excipient-Benzyl Alcohol

This article describes a simple and rapid gas chromatographic method for identification of residual solvents present in benzyl alcohol. Benzyl alcohol is used in foods and pharmaceutical products.

The organic solvents such as benzene, chlorobenzene and toluene are frequently used in manufacturing of benzyl alcohol. Even after such manufacturing process, some solvents still remain in small quantities.

Method for the quantification of residual solvents present in benzyl alcohol was done by gas chromatography with flame ionization detector and utilizes the Agilent 7700 with FID (DB-624, 30 m × 0.53 mm, 3 μ) capillary column, nitrogen as carrier gas with a flow rate of 2.5 ml mn-1.

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Literature Review of Hydrometallurgical Recycling of Printed Circuit Boards (PCBs)

This study provides an up-to-date review of recycling of printed circuit boards (PCBs), specifically in hydrometallurgical treatment.

Waste printed circuit boards, which are rich in base and precious metals, are the essential component of end-of-life electrical and electronic equipment. From the economic and environmental perspectives, the efficient recycling of PCBs is of importance.

For the extraction of metals from PCBs, a large amount of work has been done to establish an environmentally friendly and economic way to recover metals from PCBs based on physical, pyrometallurgical and hydrometallurgical processes.

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Boron Isotope Fractionation in Bell Pepper

Various plant compartments of a single bell pepper plant were studied to verify the variability of boron isotope composition in plants and to identify possible intra-plant isotope fractionation.

Boron mass fractions varied from 9.8 mg/kg in the fruits to 70.0 mg/kg in the leaves. Boron (B) isotope ratios reported as δ11B ranged from -11.0‰ to +16.0‰ (U ≤ 1.9‰, k=2) and showed a distinct trend to heavier δ11B values the higher the plant compartments were located in the plant.

A fractionation of Δ11Bleaf-roots = 27‰ existed in the studied bell pepper plant, which represents about about 1/3 of the overall natural boron isotope variation (ca. 80‰).

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