An Overview of HPTLC: A Modern Analytical Technique with Excellent Potential for Automation, Optimization, Hyphenation, and Multidimensional Applications

2010 ◽  
pp. 3-24 ◽  
Author(s):  
MM. Srivastava
Keyword(s):  
Analytical Technique ◽  
Modern Analytical Technique ◽  
Modern Analytical

Taking flame tests one step forward: the case of a DIY atomic emission spectrophotometer

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Constantina Mavroukakis-Karagounis ◽  
Isavella Papadopoulou ◽  
Myrto Papadopoulou ◽  
Christodoulos Makedonas
Keyword(s):  
Metal Ions ◽  
Atomic Emission ◽  
Calibration Procedure ◽  
Computer Interface ◽  
Analytical Technique ◽  
Modern Analytical Technique ◽  
One Step ◽  
The Cost ◽  
Modern Analytical ◽  
Final Instrument

AbstractIn the present study we report the construction of a simple atomic emission spectrophotometer and we describe its computer interface and its calibration procedure. The final instrument is employed for the detection of the presence of metal ions in commercially available drugs. The cost of the whole construction is low and it can be readily applied within the secondary education chemistry curricula in order to strengthen students’ engagement and understanding of a modern analytical technique that is based on the well known flame tests.

Phytochemical Assessment of Mimusops elengi Linn. Unripe fruits Methanol extracts using Modern Analytical Technique

2021 ◽  
pp. 3700-3704
Author(s):  
Bishwanath Mishra ◽  
Sujit Dash ◽  
Amaresh Chandra Sahoo ◽  
Prabhat Kumar Sahoo ◽  
Sazia Tabasum
Keyword(s):  
Methanol Extract ◽  
Pharmacological Action ◽  
Gas Chromatography Mass Spectrometry ◽  
Chemical Components ◽  
Molecular Formula ◽  
Analytical Technique ◽  
Modern Analytical Technique ◽  
Rf Values ◽  
Spectrometry Technique ◽  
Mimusops Elengi

Mimusops elengi Linn. is a plant with high medicinal and commercial value. Although several secondary metabolites have been reported from different species of this plant, there has been not much information available on the complete profile of phytochemical constituents in Mimusops elengi Linn. The HPTLC fingerprinting of methanol extract showed 6 peaks having maximum Rf values 0.10, 0.27, 0.34, 0.51, 0.72, and 0.80 at 254nm. The same extract showed 3 peaks having maximum Rf value 0.25, 0.29 and 0.49 at 366 nm. This study applies Gas chromatography-Mass spectrometry technique to determine the possible chemical components in the methanol extract of Mimusops elengi Linn. Unripened fruits reports for the first time most extensive profile of the plant. The determination and identification of bioactive chemical compounds is established and based on the peak area, retention time molecular weight, and molecular formula. GC-MS analysis of Mimusops elengi Linn. revealed the existence of the 2,2’ Methylenebis [3,4,6-trichloroanisole] which was found to be major component followed by Z-1,9-Hexadecadiene, Cyclopentaneundecanoic-acid, 4-Methyloctanoic acid and E-10-Dodecen-1-ol propionate. The results obtained may be helpful to the further study of pharmacological action for their promising utilization as therapeutic agents.

scholarly journals Synthesis of new Imidazole Derivatives as effective Antimicrobial Agents

2017 ◽  
Vol 5 (01) ◽  
pp. 01-09
Author(s):  
Bipin Kumar Verma ◽  
Sunil Kapoor ◽  
Umesh Kumar ◽  
Savita Pandey ◽  
Priti Arya
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Agents ◽  
Micrococcus Luteus ◽  
Bacterial Strains ◽  
Standard Drug ◽  
Mass Spectral ◽  
Analytical Technique ◽  
Imidazole Derivatives ◽  
Modern Analytical Technique ◽  
Anti Fungal

In the present work, some new imidazole derivatives (3i-xii) were synthesized as per design synthetic protocol scheme. The structures of newly prepared compounds were confirmed by modern analytical technique (IR, 1H-NMR, Mass spectral data) and elemental analysis, results found in full agreement with their assigned structures. All the synthetic compounds were screened for their antimicrobial activity against bacterial strains viz. Escherichia coli (E. coli, MTCC 2961), Staphylococcus aureus (S. aureus, MTCC 3160), Bacillus subtilis (B. subtilis, MTCC 121), Klebsiella pneumoniae (K. pneumoniae, MTCC 3040) and Micrococcus luteus (M. luteus, MTCC 7527)) and fungal strains viz. Candida albicans (C. albicans, MTCC 227), Aspergillus niger (A. niger, MTCC 277) and Aspergillus flavus (A. flavus, MTCC 418) ; results showed good to remarkable activity. The MIC (minimum inhibitory concentration) values were determined by comparison to ciprofloxacin (anti-bacterial) and fluconazole (anti-fungal) as standard drug. Among them, compound 3iv and 3x exhibited notable antimicrobial activity. These compounds may be used as new template for the searching of potential antimicrobial agents.

scholarly journals Investigation of Tobacco Pyrolysis Gases and Puff-by-puff Resolved Cigarette Smoke by Single Photon Ionisation (SPI) - Time-of-flight Mass Spectrometry (TOFMS)

2009 ◽  
Vol 23 (4) ◽  
pp. 203-226 ◽  
Author(s):  
T Adam ◽  
S Mitschke ◽  
RR Baker
Keyword(s):  
Mass Spectrometry ◽  
Cigarette Smoke ◽  
Single Photon ◽  
Time Of Flight ◽  
Analytical Technique ◽  
Decomposition Reactions ◽  
Flight Mass Spectrometry ◽  
Modern Analytical Technique ◽  
The Individual ◽  
Phd Thesis

AbstractThe work presented deals with the application of Single Photon Ionisation- Time-of-Flight Mass Spectrometry (SPI-TOFMS) for the investigation of tobacco smoke. SPI-TOFMS is a modern analytical technique, which enables the simultaneous analysis of a large number of organic species in complex gas mixtures in real time. The paper is a summary of a PhD thesis (1) and seven research articles, which were recently published in various scientific journals (2-8). Consequently, more detailed information on particular aspects can be found in there.The experimental part covers two different approaches, and therefore, it is divided into two sub-sections. In the first one, the SPI-TOFMS is coupled to a pyrolysis furnace. The objective is to examine the thermal behaviour of tobacco under various controlled conditions. In so doing, three tobacco types (Virginia, Oriental, and Burley) were pyrolysed in two reaction gas compositions (nitrogen and synthetic air) and seven different furnace temperatures (400 °C, 500 °C, 600 °C, 700 °C, 800 °C, 900 °C, and 1000 °C). Results can help to unravel the complex formation and decomposition reactions taking place when tobacco is heated. In the second part the SPI-TOFMS is connected to a cigarette smoking machine in order to investigate the behaviour of cigarette smoke constituents on a puff-by-puff basis. The work incorporates the comparison of whole smoke and gas phase of cigarette smoke, a puff-resolved quantification of several hazardous smoke constituents, and the overall chemical characterisation of the individual smoking puffs. In addition, a critical consideration of the prevailing smoking procedure is given when applied to single puff analysis. A further study examines the influence of five different cigarette lighting devices (gas lighter, electric lighter, candle, match, and burning zone of another cigarette) on the chemical composition of the first puff.

Trends in Electron Energy Loss Spectroscopy

1977 ◽  
Vol 35 ◽  
pp. 228-229
Author(s):  
C. Colliex ◽  
P. Trebbia
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Electron Energy Loss Spectroscopy ◽  
Materials Science ◽  
Analytical Technique ◽  
Recent Developments ◽  
Quantitative Results ◽  
Electron Microscopes ◽  
Electron Energy Loss ◽  
Primary Electrons

The physical foundations for the use of electron energy loss spectroscopy towards analytical purposes, seem now rather well established and have been extensively discussed through recent publications. In this brief review we intend only to mention most recent developments in this field, which became available to our knowledge. We derive also some lines of discussion to define more clearly the limits of this analytical technique in materials science problems.The spectral information carried in both low ( 0<ΔE<100eV ) and high ( >100eV ) energy regions of the loss spectrum, is capable to provide quantitative results. Spectrometers have therefore been designed to work with all kinds of electron microscopes and to cover large energy ranges for the detection of inelastically scattered electrons (for instance the L-edge of molybdenum at 2500eV has been measured by van Zuylen with primary electrons of 80 kV). It is rather easy to fix a post-specimen magnetic optics on a STEM, but Crewe has recently underlined that great care should be devoted to optimize the collecting power and the energy resolution of the whole system.

Spatially Resolved Photoelectron Spectroscopy: Recent Progress and Future Plans

1990 ◽  
Vol 48 (2) ◽  
pp. 388-389
Author(s):  
A. M. Bradshaw
Keyword(s):  
Photoelectron Spectroscopy ◽  
Chemical Reactivity ◽  
Target Material ◽  
Orbital Energy ◽  
Light Sources ◽  
Analytical Technique ◽  
Hartree Fock ◽  
Spatially Resolved ◽  
Koopmans Theorem ◽  
Surface Analytical Technique

X-ray photoelectron spectroscopy (XPS or ESCA) was not developed by Siegbahn and co-workers as a surface analytical technique, but rather as a general probe of electronic structure and chemical reactivity. The method is based on the phenomenon of photoionisation: The absorption of monochromatic radiation in the target material (free atoms, molecules, solids or liquids) causes electrons to be injected into the vacuum continuum. Pseudo-monochromatic laboratory light sources (e.g. AlKα) have mostly been used hitherto for this excitation; in recent years synchrotron radiation has become increasingly important. A kinetic energy analysis of the so-called photoelectrons gives rise to a spectrum which consists of a series of lines corresponding to each discrete core and valence level of the system. The measured binding energy, EB, given by EB = hv−EK, where EK is the kineticenergy relative to the vacuum level, may be equated with the orbital energy derived from a Hartree-Fock SCF calculation of the system under consideration (Koopmans theorem).

Recent developments in low-voltage SEM of polymers

1993 ◽  
Vol 51 ◽  
pp. 866-867
Author(s):  
S.J. Krause ◽  
W.W. Adams
Keyword(s):  
Low Voltage ◽  
Chromatic Aberration ◽  
Thermal Electron ◽  
Analytical Technique ◽  
Recent Developments ◽  
Beam Currents ◽  
New Generation ◽  
First Time ◽  
Voltage Scanning ◽  
Beam Damage

Over the past decade low voltage scanning electron microscopy (LVSEM) of polymers has evolved from an interesting curiosity to a powerful analytical technique. This development has been driven by improved instrumentation and in particular, reliable field emission gun (FEG) SEMs. The usefulness of LVSEM has also grown because of an improved theoretical and experimental understanding of sample-beam interactions and by advances in sample preparation and operating techniques. This paper will review progress in polymer LVSEM and present recent results and developments in the field.In the early 1980s a new generation of SEMs produced beam currents that were sufficient to allow imaging at low voltages from 5keV to 0.5 keV. Thus, for the first time, it became possible to routinely image uncoated polymers at voltages below their negative charging threshold, the "second crossover", E2 (Fig. 1). LVSEM also improved contrast and reduced beam damage in sputter metal coated polymers. Unfortunately, resolution was limited to a few tenths of a micron due to the low brightness and chromatic aberration of thermal electron emission sources.

Parallel Combining Different Approaches to Multi-pattern Matching for Fpga-based Security Systems

2017 ◽  
Vol 5 (1) ◽  
pp. 8-15
Author(s):  
Sergii Hilgurt ◽  
Keyword(s):  
Information Security ◽  
Pattern Matching ◽  
Intrusion Detection System ◽  
Detection System ◽  
Finite Automata ◽  
Network Intrusion Detection ◽  
Security Systems ◽  
Analytical Technique ◽  
Network Intrusion ◽  
Pros And Cons

The multi-pattern matching is a fundamental technique found in applications like a network intrusion detection system, anti-virus, anti-worms and other signature- based information security tools. Due to rising traffic rates, increasing number and sophistication of attacks and the collapse of Moore’s law, traditional software solutions can no longer keep up. Therefore, hardware approaches are frequently being used by developers to accelerate pattern matching. Reconfigurable FPGA-based devices, providing the flexibility of software and the near-ASIC performance, have become increasingly popular for this purpose. Hence, increasing the efficiency of reconfigurable information security tools is a scientific issue now. Many different approaches to constructing hardware matching circuits on FPGAs are known. The most widely used of them are based on discrete comparators, hash-functions and finite automata. Each approach possesses its own pros and cons. None of them still became the leading one. In this paper, a method to combine several different approaches to enforce their advantages has been developed. An analytical technique to quickly advance estimate the resource costs of each matching scheme without need to compile FPGA project has been proposed. It allows to apply optimization procedures to near-optimally split the set of pattern between different approaches in acceptable time.

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