Low Molecular Weight Alcohols Research Articles

Use of carbonyldiimidazole as a derivatization agent for the detection of pinacolyl alcohol, a forensic marker for Soman, by EI-GC-MS and LC-HRMS in official OPCW proficiency test matrices.

Pinacolyl alcohol (PA), a key forensic marker for the nerve agent Soman (GD), is a particularly difficult analyte to detect by various analytical methods. In this work, we have explored the reaction between PA and 1,1'-carbonyldiimidazole (CDI) to yield pinacolyl 1H-imidazole-1-carboxylate (PIC), a product that can be conveniently detected by gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-high-resolution mass spectrometry (LC-HRMS). Regarding its GC-MS profile, this new carbamate derivative of PA possesses favorable chromatographic features such as a sharp peak and a longer retention time (RT = 16.62 min) relative to PA (broad peak and short retention time, RT = 4.1 min). The derivative can also be detected by LC-HRMS, providing an avenue for the analysis of this chemical using this technique where PA is virtually undetectable unless present in large concentrations. From a forensic science standpoint, detection of this low molecular weight alcohol signals the past or latent presence of the nerve agent Soman (GD) in a given matrix (i.e., environmental or biological). The efficiency of the protocol was tested separately in the analysis and detection of PA by EI-GC-MS and LC-HRMS when present at a 10 μg/mL in a soil matrix featured in the 44th PT and in a glycerol-rich liquid matrix featured in the 48th Official Organization for the Prohibition of Chemical Weapons (OPCW) Proficiency Test when present at a 5 μg/mL concentration. In both scenarios, PA was successfully transformed into PIC, establishing the protocol as an additional tool for the analysis of this unnatural and unique nerve agent marker by GC-MS and LC-HRMS.

A Limited Number of Amino Acid Permeases Are Crucial for Cryptococcus neoformans Survival and Virulence.

One unique attribute of Cryptococcus neoformans is its ability to procure essential monomers from its surroundings to survive in diverse environments. Preferentially, sugars are the energy sources for this opportunistic pathogenic fungus under the carbon catabolite repression (CCR); however, sugar restriction induces alternative use of low molecular weight alcohol, organic acids, and amino acids. The expression of transmembrane amino acid permeases (Aaps) allows C. neoformans to utilize different amino acids and their conjugates, notwithstanding under the nitrogen catabolite repression (NCR). Being referred to as global permeases, there is a notion that all cryptococcal Aaps are important to survival and virulence. This functional divergence makes alternative drug targeting against Cryptococcus a challenge. We examine the functions and regulations of C. neoformans Aap variants with the aim of rationalizing their relevance to cryptococcal cell survival and virulence. Based on nutrient bioavailability, we linked the Cac1 pathway to Ras1 activation for thermotolerance that provides a temperature cushion for Aap activity under physiological conditions. Lastly, mutants of Aaps are examined for significant phenotypic deficiencies/advantages, which buttress the specific importance of limited numbers of Aaps involved in cryptococcal infections.

A Multiple Stimuli-Responsive Ag/P/S Complex Showing Solvochromic and Mechanochromic Photoluminescence.

The reaction of CF3COOAg, 3-bdppmapy (N,N-bis(diphenylphosphanylmethyl)-3-aminopyridine) and HTZ (1,2,4-triazole-3-thiol) in CH2Cl2/MeOH resulted in a dinuclear Ag/P/S complex [Ag2(TZ)2(3-bdppmapy)2]·xSol (1·xSol). Crystals of 1·xSol converted to 1·2MeOH in air at room temperature and further to 1 under vacuum upon heating. The solid-state, room-temperature photoluminescent emission of 1·xSol (510 nm) shifted to 494 nm (1·2MeOH) and 486 nm (1). Grinding solids of 1·2MeOH in air resulted in amorphous 1G characterized by solid-state emission at 468 nm, which converted to 1GR with 513 nm emission upon MeOH treatment. Grinding 1GR in air returned 1G, and this interconversion was reproducible over five cycles. The solid-state photoluminescence of 1G changed in response to vapors containing low-molecular weight alcohols but remained unchanged after exposure to other volatile organic compounds (VOCs) or to water vapor. Test papers impregnated with 1G could detect methanol in vapors from aqueous solutions at concentrations above 50%. Complex 1G is, therefore, an example of a stimuli-responsive molecular sensor for the detection of alcohols.

Preferential solvation and solvato(fluor)chromism of a green synthesized carbon nanodots in aqueous low molecular weight alcohols

Solvent medium effects on the optical spectra of a carbon nanodot (C-dots) as a solvato(fluor)chromic indicator have been investigated. The molar fluorescence transition energies of C-dots in different aqueous low molecular weight alcohols (C1-C3) were interpreted in terms of the Kamlet, Abboud and Taft equation. Emission results demonstrate that acidity is the most influential feature for the case of lighter methanol and ethanol, whereas the polarizability of the mixed solvent was the dominant factor for the propanol. The preferential solvation of the C-dots under consideration in the mixed water/alcohol solvents has been studied and were analyzed using two different models. In words, solvent exchange process and an excess function model were employed to evaluate the extent of preferential solvation. Correspondingly, both models exploited, confirmed the tendency of C-dots to be preferably solvated by alcohols rather than water. Interestingly, with an increase in the length of the alcohol carbon chain the extent of preferential solvation illustrated a decreasing trend.

Electrochemical study of Bismuth heavy metals using the cyclic voltammetry method in anti-protozoal

Bismuth oxides are well-known electro-catalysts in fuel cells systems; they are usually used as anodic materials for the oxidation of low molecular weight alcohols. The utilization of BiO2 and MnO2 as catalysts in the pharmaceutical analysis is analytical method for the determination of heavy metal antibacterial agents in Pharmaceutical Dosage form is developed. The method is based on the voltammetric determination of heavy metal using Bidified platinum electrode by Bismuth oxide. The two components are oxidized at the Bidified electrode surface with the development of current that is linearly proportional to their concentrations in the range of 7.04*10-7- 1*10-3 M heavy metal. The oxidation reaction of the two components is pH-dependent, in which the buffer used is Britton-Robinson at pH = 7.00 where maximum peak current and maximum peak separation is obtained. The regression factors obtained from the calibration curves are 0.9812. The method of analysis was validated, where the limit of detection (LOD) and the limit of quantitation (LOQ) were calculated to be 1.44*10-4 M, 4.36*10-4 M and 1.27*10-4 M, 3.84*10-4 M respectively, the percentage recovery of both components was also calculated to 77 % for heavy metal.

Computing dissipative particle dynamics interactions to render molecular structure and temperature-dependent properties of simple liquids

Simulating structural and thermodynamical properties of liquids has always been a challenge. Typical examples of liquids that demonstrate particular structure and properties are water and the low molecular weight alcohols, for which hydrogen bond interactions lead to their distinctive properties, such as cage-like structures and temperature-dependent properties. Modeling these materials at the coarse-grained level is even a bigger challenge due to the loss of atomistic-level interactions. Nevertheless, one is interested in mimicking these typical properties at the coarse-grained level due to the relevance of these systems in complex environments, for which fully atomistic simulations still remain a challenge. In this paper, we introduce a mesoscopic level parameterization of DPD interactions to study the particular structural and thermodynamic properties of liquid water, methanol, ethanol and 1-propanol. The conservative repulsive DPD interactions are explicitly computed by a bottom-up parameterization, in which experimental thermodynamics data are used. A previously developed statistical mechanics approach is used to compute the hydrogen bond strength. The transport properties, such as viscosity, and thermodynamical properties, such as isothermal compressibility, are found to agree reasonably well with experimental data. Moreover, the structure as characterized by the radial distribution function and angular distributions of three neighboring molecules are in line with the atomistic simulations performed in this work. Furthermore, the temperature-dependency of the repulsive DPD interactions is modeled by incorporating the experimental isothermal compressibilities at different temperatures. The effect of the temperature on the hydrogen bond strengths is considered as well and the structural properties are predicted via the DPD simulations. In general, our work can be viewed as an attempt to model systems by the DPD simulations, where hydrogen bonds play a crucial role. The computed parameterization of DPD interactions is believed to pave the way towards extending the current applicability of DPD method to more complex systems.

Effect of Lactic Acid Bacteria on the Quality Attributes of Tea-Like Product from Blends of Drumstick (Moringa oleifera) Leaves and Ginger (Zingiber officinale)

Moringa oleifera leaves and Ginger crops still remain an underutilized commodity because of limited information on its wider use. Moringa oleifera is very rich in nutrition but has undesirable taste and flavor. However, addition of ginger takes the edge off the bitter spinachy taste of Moringa oleifera leaves. Lactic acid bacteria (LAB) are important microbes that have long been used in both traditional and modern industrial food fermentation. Lactic acid bacteria can be used for production of food due to their ability to coax microorganisms into producing In the process of food fermentation; microorganisms produce enzymes to break down complex compounds to simple bio-molecules for several biological activities such as proteinase, amylase, mannase, cellulase, and catalase. The aim of this research work is to determine the effect of Lactic acid bacteria (LAB) fermentation on the quality attributes of tea-like beverage produced from blends of Moringa oleifera leaves and Ginger(Zingiber officinale). The results showed that The phenotypic and biochemical characteristic of Blends of Drumstick leaves (Moringa oleifera) and Ginger (Zingiber officinale) reveals that the isolates were presumptively categorized to belong to the genus Lactobacillus, the isolates are gram positive, cocci, rod shaped, either, short rod or long rods, non-sporulating, ferments carbohydrate, non-motile and catalase negative. Technological properties of isolates are the properties that indicate the quality of the isolate to be used as a starter culture in the course of fermentation. A total of 35 colonies were isolated from the blend samples. Of them, 3 colonies were identified as Lactobacillus species, through observation of phenotypic characters, and identification, It was found that L. plantarum had tolerance under acid conditions, as its viable cell count remained at pH 2.0 and under 1.0 % bile salt condition, after 72 h incubation time. The proximate and energy content of fermented beverage produced from the blends shows that percent Dry matter, Moisture content, Crude protein, Ether extract , Crude fibre, Ash, carbohydrate and energy value were ranged from 10.00- 30.00, 4.0-5.0, 35.00 -71.00, 3.0-5.0, 11.00 - 18.00,3.0-10,7.0-15 and 74Kcal - 396Kcal respectively. The study concludes that The phenotypic and biochemical characteristic of blends of drum stick leaves (Moringa oleifera) and Ginger (Zingiber officinale) reveals that the isolates were to belong to the genus Lactobacillus. Also, Many of the LAB metabolites such as low molecular weight acids, alcohols, carbon dioxide, diacetyl and hydrogen peroxides have broad spectrum antimicrobial activity against other species of bacteria. The proximate and energy value of the beverage plays a crucial role in assessing its nutritional significance (P<0.05). Consequently, the fermentation of these blends with LAB species might provide a means of retaining more of the nutrients that are trapped in the matrix of the cells of these plant materials.

Cellulose Degradation and Transformer Fault Detection by the Application of Integrated Analyses of Gases and Low Molecular Weight Alcohols Dissolved in Mineral Oil

This article presents a method for quantification of methanol and ethanol integrated in the same gas-chromatographic run with a quantification of gases dissolved in mineral oil, making it an integrated tool in transformer diagnostics. The results of aging experiments at 120 °C and 60 °C of Kraft paper, copper, barrier, and pressboard immersed in mineral oil, as well as the aging of thermal upgrade paper in mineral and natural ester oil at 140 °C are presented, in order to investigate correlations between different aging markers and to evaluate their partitioning between oil and cellulose at defined conditions. The results of partitioning experiments at 60 °C showed that re-absorption of methanol from oil to the cellulose materials is faster than the re-absorption of furans. This means that methanol is a paper-degradation marker that can be used in diagnostics over shorter equilibrium times and for the detection of developing faults at broader temperature ranges. Furthermore, a statistical overview of methanol concentration from a database and two transformer fault diagnostic cases are presented. Therefore, in addition to an analysis of gases dissolved in oil, the use of methanol and ethanol in transformer fault and failure investigations should be explored and verified through transformer fault investigations and postmortem analyses.

PYROLYTIC MASS-SPECTROMETRY OF THE OLIGOISOPRENE WITH OF TERMINAL HYDROXYL GROUPS

Pyrolytic mass spectrometry was used to evaluate the effect of terminal hydroxyl groups on the composition of thermal degradation products of oligoisoprene obtained using hydrogen peroxide as an initiator in the isopropyl alcohol solution. To interpret the mass spectra of the oligomer, the mass spectra of some low molecular weight alcohols were used. Oxygen-containing groups were found in the mass spectrum of the oligomer, confirming the presence of two types of hydroxyl groups. Peak m/z = 85 corresponds to the fragment from the terminal unit of isoprene directly connected with the primary hydroxyl group, and peak m/z = 127 does the same unit with the terminal fragment of isopropyl alcohol with the tertiary hydroxyl group. This conclusion is confirmed by the presence of peaks resulting from the transformations of the end groups of atoms in the oligomer, which are modeled by the corresponding low molecular weight alcohols.

RELATİONSHİP BETWEEN ELECTRICAL AND CATALYTIC IN THE REACTION OF CONVERSION OF ETHANOL TO ACETONE

Low molecular weight ketones are among the most important products widely used in industry, however, the existing methods for their production are multistage. The significant disadvantages of these methods include the implementation of individual stages at high temperatures and pressures. As a result, the development of more economical and easy-to-implement processes is presented as an actual task for the basic organic synthesis industry. Recently, ethanol has been considered as a possible feedstock for the production of acetone. The prospect of using ethanol as a feedstock is due to the large renewable resources for its production. The growing interest in recent years in the production of ethanol by processing agricultural products and waste from the food and woodworking industries will undoubtedly stimulate further development of the method of producing acetone from ethanol. The catalytic conversion of ethanol to acetone is a relatively new method for producing acetone and, naturally, the number of publications devoted to this process is relatively small. In previously published works, as a rule, the issues of the mechanism of the process, as well as the relationship between the physicochemical and catalytic properties of the proposed active systems in these reactions, are not considered in detail. Active and selective catalysts were selected for the conversion reaction of ethanol to acetone, the mechanism of the process and the relationship between the physicochemical and catalytic properties of the activated sample were studied. The experiments were carried out on an active catalyst with the composition ZnO:CaO=9:1 The main provisions of the electronic theory of catalysis are developed in application to semi¬con-ductors, since, firstly, the theory of semiconductors is now more developed, and secondly, most of the catalysts used in practice belong to semiconductors. The surface of a semiconductor is the protection of two phases: a solid body-gas. The approach to this boundary from the side of the gaseous environment is essential for catalysis. The environment affects the surface and volume of the solid body. The influence of the environment is carried out through adsorption, as a result, the Fermi level shifts, and the electrophysical pro¬pert¬ies of catalysts change in the processes of adsorption and catalysis. Reactions of heterogeneous-catalytic transformation of low molecular weight alcohols are of great practical importance. The relevance of catalytic transformations of ethanol into various valuable products is the most important task of modern catalytic chemistry. To elucidate the mechanism of these reactions, a necessary step is to study the nature of the electronic interaction of reactants with a solid body, since the vast majority of catalysts of heterogeneous-catalytic oxidation - metal oxides, semiconductors, so especially promising is to involve methods for studying the electro physical properties of the surface. Changing these properties and studying the nature of their change in the atmosphere of the reactants, it is possible obtain valuable information about the nature of the electronic interaction of the reactant-catalyst. The works carried out in this direction showed that in most cases the process of chemisorption is accompanied by the appearance of an additional surface potential, indicating the charging of the surface in the presence of a particular reactant. The electrical and catalytic properties of a series of active zinc-calcium oxide catalysts were studied (their activity was also studied in previous experiments). The study of the electrical properties of the catalyst is of the greatest interest for elucidating the mechanism of reactions, since they can provide information about the nature of electronic transitions that limit the course of the reaction. The number of different factors determines the catalytic activity of a solid body. Each of these factors can correlate with certain properties of a solid body. When comparing catalytic and electrophysical properties electrical conductivity is most often measured. Measuring on the same catalyst sample under the same conditions of conductivity change can provide useful information about mechanism of action of the catalyst and the course of the catalytic reaction. Studies of the electrical conductivity of the synthesized catalysts have shown that all the catalysts studied are semiconductors. This article shows the relationship between the electrical and catalytic properties of zinc-calcium oxide catalysts. Keywords: catalyst, electrical conductivity, activation energy, adsorption, ethanol, acetone.

Experimental analysis of diesel fuel properties with blended Mahua oil biodiesel for CI engines

The experimental research work done here in this study reveals the consequence of biodiesel blending on the characteristics of CI (diesel) engine and its performance. In this paper Biodiesel obtained from Mahua oil is experimented, its preparation is through the two-step transesterification process in the presence of low molecular weight alcohols for example methanol and a base such as sodium hydroxide. Research experiments were conducted so as for the evaluation of the experimental performance parameters of a 1-cylinder, water-cooled and four strokes, direct injection Compression Ignition (CI) engine with the above mentioned specially prepared Mahua oil for better results. The experiments were observed with thrice attempts and the results obtained from all the fuel blends were thoroughly formulated, analysed and compared with clean mineral diesel available in the market used in automotive sector.

Selection by UV Mutagenesis and Physiological Characterization of Mutant Strains of the Yeast Saprochaete suaveolens (Former Geotrichum fragrans) with Higher Capacity to Produce Flavor Compounds.

Yeast volatile organic compounds (VOCs), i.e. low molecular weight organic acids, alcohols and esters, are considered as potential and sustainable sources of natural aromas that can replace commonly used artificial flavors in food and other industrial sectors. Although research generally focuses on the yeast Saccharomyces cerevisiae, other so-called unconventional yeasts (NCY) are beginning to attract the attention of researchers, particularly for their ability to produce alternative panels of VOCs. With this respect, a Saprochaete suaveolens strain isolated from dragon fruit in Reunion Island was shown to produce α-unsaturated esters from branched-chain amino acids (BCAAs) such as isobutyl, isoamyl or ethyl tiglate, which are rarely found in other yeasts strains. Given that β-oxidation allows the growth of S. suaveolens on BCAAs as sole carbon source, we developped a method based on UV mutagenesis to generate mutants that can no longer grow on BCAAs, while redirecting the carbon flow towards esterification of α-unsaturated esters. Among the 15,000 clones generated through UV irradiation, we identified nine clones unable to grow on BCAAs with one of them able to produce eight times more VOCs as compared to the wild-type strain. This higher production of α-unsaturated esters in this mutant strain coincided with an almost complete loss of enoyl-CoA hydratase activity of the β-oxidation pathways and with a twofold increase of acyl-CoA hydrolase with not significant changes in the enzymes of the Ehrlich pathway. Moreover, from our knowledge, it constituted the first example of VOCs enhancement in a microbial strain by UV mutagenesis.

Diffusive and capillary instabilities of viscous fluid threads in microchannels

We experimentally investigate the flow behavior of viscous oil threads in a a variety of miscible and immiscible low-molecular weight alcohols in microchannels. A comparative study is conducted between diffusive and capillary regimes using simple functional relationships for the thread characteristics, including diameter and detachment length. We develop a comprehensive classification of immiscible and miscible fluid dynamics in square microfluidic channels and provide a quantitative analysis of the evolution of multiphase flow properties across flow patterns.

Electrochemical Analysis of Heavy metal by Cyclic Voltammetry Method

Bismuth and Bismuth oxides are well-known electro-catalysts in fuel cells systems; they are usually used as anodic materials for the oxidation of low molecular weight alcohols. The utilization of BiO2 and MnO2 as catalysts in the pharmaceutical analysis is analytical method for the determination of heavy metal antibacterial agents in Pharmaceutical Dosage form is developed. The method is based on the voltammetric determination of heavy metal using Bidified platinum electrode by Bismuth oxide. The two components are oxidized at the Bidified electrode surface with the development of current that is linearly proportional to their concentrations in the range of 7.04*10-7- 1*10-3 M heavy metal. The oxidation reaction of the two components is pH-dependent, in which the buffer used is Britton-Robinson at pH = 7.00 where maximum peak current and maximum peak separation is obtained. The regression factors obtained from the calibration curves are 0.9812. The method of analysis was validated, where the limit of detection (LOD) and the limit of quantitation (LOQ) were calculated to be 1.44*10-4 M, 4.36*10-4 M and 1.27*10-4 M, 3.84*10-4 M respectively, The percentage recovery of both components was also calculated to 77 % for heavy metal.

Effect of Anode Material on Electrochemical Oxidation of Low Molecular Weight Alcohols-A Review.

The growing climate crisis inspires one of the greatest challenges of the 21st century—developing novel power sources. One of the concepts that offer clean, non-fossil electricity production is fuel cells, especially when the role of fuel is played by simple organic molecules, such as low molecular weight alcohols. The greatest drawback of this technology is the lack of electrocatalytic materials that would enhance reaction kinetics and good stability under process conditions. Currently, electrodes for direct alcohol fuel cells (DAFCs) are mainly based on platinum, which not only provides a poor reaction rate but also readily deactivates because of poisoning by reaction products. Because of these disadvantages, many researchers have focused on developing novel electrode materials with electrocatalytic properties towards the oxidation of simple alcohols, such as methanol, ethanol, ethylene glycol or propanol. This paper presents the development of electrode materials and addresses future challenges that still need to be overcome before direct alcohol fuel cells can be commercialized.

Separation of low molecular weight alcohols from water with deep eutectic solvents: Liquid-liquid equilibria and process simulations

Low molecular weight alcohols such as ethanol, propanol and butanol are currently gaining attention owing to their complete combustion and higher calorific value. These low molecular weight alcohols are obtained by ABE (acetone−butanol−ethanol) fermentation, where they are produced within an aqueous phase. Extraction is contemplated as one of the effective methods for the separation of these lower alcohols from aqueous phase through a solvent. The solvent explored here relates to the formulation of Deep Eutectic Solvent (DES) comprising of DL-menthol (Hydrogen Bond Donor) + decanoic acid (Hydrogen Bond Acceptor). The current work adopts a multiscale approach leading with DES preparation and subsequent batch scale Liquid-Liquid Equilibria (LLE) measurement and finally concludes through process simulation studies. The experimental LLE data of DES (1)-Alcohol (2)-Water (3) gave a higher affinity towards alcohol and lower solubility with water. The experimental results were thereafter regressed with the NRTL model using the additional constraint where a positive tangent plane distance is imposed for all the tie lines within the Gibbs energy of mixing (Gm) surface. The average absolute RMSD values correlated via NRTL and COSMO-SAC model were found to be 0.003 and 0.008 respectively. A flow sheet with a hybrid extraction-distillation system is then proposed and simulated for the solvent recovery, scale-up and cost analysis.

A photoluminescent Au(I)/Ag(I)/PNN coordination complex for relatively rapid and reversible alcohol sensing.

Trinuclear complex [Au2Ag(dppmaphen)2(CN)2]PF6 photoluminesces on exposure to low molecular weight alcohols. This emission is likely due to C-Hπ interactions between the analyte and -PPh2 group, that inhibits non-radiative relaxation of the photoexcited state. Photoluminescene was quenched by removing the analyte under a stream of N2 or replacing it with H2O. This on/off switching was clearly visible, relatively rapid and recyclable.

Optimization of Vegetable Oil-Based Biodiesels by Multi-Response Surface Methodology (MRS) using Desirability Functions

Environmental concerns associated with petroleum resources have propelled the development of sustainable and renewable alternatives to petroleum based products. Vegetable oil is one amongst the foremost abundant bio-based feedstocks. The interest in using vegetable oils and low molecular weight alcohols by direct transesterification have shown great potential as alternatives to petroleum-based diesel, and the production of bio-based diesel continues to increase. Utilization of multi-response surface methodology (MRS) for the most effective combination effect or response from the uses of input to output variables to optimize the yield and higher heating values (HHV) of biodiesels was investigated. In this work, utilizing variety of non-edible vegetable oils like castor (Ricinus communis L), jatropha (Jatropha curcas), and neem (Azadirachta indica) seeds and several process variables or inputs, including mixing time, mixing speed, process temperature and catalyst dosage to formulate high quality renewable fuels were further explored. The outputs were yield, viscosity, higher heating value, density and turbidity. The proposed optimization scenarios for biodiesel using the statistical (MRS) models was aimed to optimize the processes to achieved high conversion and higher heating values, while reducing the reaction time, turbidity, density, and viscosity in the samples. The results showed catalyst dosage as the most important variable for all the three samples. For maximum yield of 100%, the molar ratio of 6.25, catalyst of 0.75 wt.%, reaction speed of 499.99 rpm, reaction time of 19.88 min and temperature of 24.50 oC were found as optimal conditions; while the molar ratio of 5.60, catalyst of 1.01 wt.%, the reaction speed of 499.5 rpm, reaction time of 20.00 min and temperature of 35.50 oC were optimal conditions for maximum biodiesel yield.

Electrochemical Analysis of Heavy metal by Cyclic Voltammetry Method

Bismuth and Bismuth oxides are well-known electro-catalysts in fuel cells systems; they are usually used as anodic materials for the oxidation of low molecular weight alcohols. The utilization of BiO2 and MnO2 as catalysts in the pharmaceutical analysis is analytical method for the determination of heavy metal antibacterial agents in Pharmaceutical Dosage form is developed. The method is based on the voltammetric determination of heavy metal using Bidified platinum electrode by Bismuth oxide. The two components are oxidized at the Bidified electrode surface with the development of current that is linearly proportional to their concentrations in the range of 7.04*10-7 - 1*10-3 M heavymetal. The oxidation reaction of the two components is pH-dependent, in which the buffer used is Britton-Robinson at pH = 7.00 where maximum peak current and maximum peak separation is obtained. The regression factors obtained from the calibration curves are 0.9812. The method of analysis was validated, where the limit of detection (LOD) and the limit of quantitation (LOQ) were calculated to be 1.44*10-4 M, 4.36*10-4 M and 1.27*10-4 M, 3.84*10-4 M respectively, The percentage recovery of both components was also calculated to 77 % for heavy metal.

Reversible chemocapacitor system based on PDMAEMA polymers for fast sensing of VOCs mixtures

A sensing system, based on tailor-made qPDMAEMA polymers, with the ability to discriminate between methanol and ethanol vapors in the presence or absence of humidity without the need of a separation column and at room temperature is designed and implemented. The miniaturized sensing system is comprised of four polymer coated planar capacitors along with the readout electronic module. The capacitors are fabricated with mainstream microelectronic/micromachining processes forming a planar InterDigitated Electrodes outline with 1 μm critical dimension. Tailor-made, hydrophilic homopolymers and a copolymer based on poly((2-dimethylamino)ethyl methacrylate), synthesized via GTP and quaternized with either methyl iodide or 1-(chloromethyl)naphthalene were used as the sensing layer and were compared to a hydrophobic, commercially available polymer. The sensing system was evaluated upon exposure to humidity, volatile organic compounds and binary mixtures of the latter. Data processing with Principal Component Analysis (PCA) highlights the ability of the proposed sensing system to discriminate between polar analytes, and more importantly between low molecular weight alcohol vapors, ethanol and methanol, in the presence of humidity.