ANALYTICAL TECHNIQUES | Hyphenated Chromatographic-Spectroscopic Techniques

2000 ◽  
pp. 153-155
Author(s):  
K.P. Kirkbride
Keyword(s):  
Analytical Techniques ◽  
Spectroscopic Techniques

scholarly journals Fraud in Animal Origin Food Products: Advances in Emerging Spectroscopic Detection Methods over the Past Five Years

Foods ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1069 ◽  
Author(s):  
Abdo Hassoun ◽  
Ingrid Måge ◽  
Walter F. Schmidt ◽  
Havva Tümay Temiz ◽  
Li Li ◽  
...  
Keyword(s):  
Analytical Techniques ◽  
Food Products ◽  
Alternative Methods ◽  
Detection Methods ◽  
Animal Origin ◽  
Spectroscopic Techniques ◽  
Food Fraud ◽  
The Past ◽  
Art Research ◽  
Animal Origin Food

Animal origin food products, including fish and seafood, meat and poultry, milk and dairy foods, and other related products play significant roles in human nutrition. However, fraud in this food sector frequently occurs, leading to negative economic impacts on consumers and potential risks to public health and the environment. Therefore, the development of analytical techniques that can rapidly detect fraud and verify the authenticity of such products is of paramount importance. Traditionally, a wide variety of targeted approaches, such as chemical, chromatographic, molecular, and protein-based techniques, among others, have been frequently used to identify animal species, production methods, provenance, and processing of food products. Although these conventional methods are accurate and reliable, they are destructive, time-consuming, and can only be employed at the laboratory scale. On the contrary, alternative methods based mainly on spectroscopy have emerged in recent years as invaluable tools to overcome most of the limitations associated with traditional measurements. The number of scientific studies reporting on various authenticity issues investigated by vibrational spectroscopy, nuclear magnetic resonance, and fluorescence spectroscopy has increased substantially over the past few years, indicating the tremendous potential of these techniques in the fight against food fraud. It is the aim of the present manuscript to review the state-of-the-art research advances since 2015 regarding the use of analytical methods applied to detect fraud in food products of animal origin, with particular attention paid to spectroscopic measurements coupled with chemometric analysis. The opportunities and challenges surrounding the use of spectroscopic techniques and possible future directions will also be discussed.

Lasers in the Analysis of Cultural Heritage Materials

2009 ◽  
Vol 8 ◽  
pp. 47-60 ◽  
Author(s):  
Demetrios Anglos ◽  
Savas Georgiou ◽  
Costas Fotakis
Keyword(s):  
Remote Sensing ◽  
Chemical Composition ◽  
Fluorescence Spectroscopy ◽  
Cultural Heritage ◽  
Molecular Level ◽  
Analytical Techniques ◽  
Spectroscopic Techniques ◽  
Works Of Art ◽  
Non Linear ◽  
Detector Technology

This article reviews laser-based analytical techniques, which find applications in the field of cultural heritage diagnostics, providing information about the chemical composition of materials, at the atomic or molecular level. Lasers are intense sources of light featuring unique characteristics that have been exploited in order to enhance the performance of certain spectroscopic techniques such as Raman or fluorescence spectroscopy, or even produce new schemes of analysis, including, for instance, non-linear or remote sensing spectroscopy as well as laser ablative sampling and excitation. In parallel, with advances in laser and detector technology, compact, mobile instrumentation is becoming available that permits broader use of such laser-based techniques for analysis of materials in works of art and archaeological findings.

Classification of Fertilizer Solutions by Micro-Volume Voltammetric Electronic Tongue with Two Sensing Electrodes

2015 ◽  
Vol 1131 ◽  
pp. 131-134 ◽  
Author(s):  
Thanawee Chodjarusawad ◽  
Kanjana Saeteaw ◽  
Darinee Phromyothin ◽  
Supanit Porntheeraphat ◽  
Rungroj Maolanon ◽  
...  
Keyword(s):  
Electronic Tongue ◽  
Reference Electrode ◽  
Analytical Techniques ◽  
Spectroscopic Techniques ◽  
Different Types ◽  
Dracaena Sanderiana ◽  
Voltammetric Electronic Tongue ◽  
Fertilizer Solutions ◽  
Good Agreement

A micro-volume electronic tongue based on cyclic voltammetry with two sensing electrodes (gold and carbon) and a platinum pseudo-reference electrode is proposed to classify fertilizers and monitor fertilizer uptakes. The electronic tongue has been employed to classify three different types of commercial fertilizers and their mixture. The nutrient uptake of Dracaena Sanderiana (D. Sanderiana) planted in crystal soil with the mixture fertilizer was monitored by sampling the fertilizer solutions with the electronic tongue over a period of one week. The contents of macronutrients in the solutions were also analyzed by the standard spectroscopic techniques for comparison. A good agreement is obtained between the relative uptakes of phosphate and potassium from the electronic tongue analysis and those from the standard analytical techniques.

Importance And Ill-Effects Of Nanoparticles: Sensors For Its Identification

2020 ◽  
Vol 16 ◽  
Author(s):  
Vallidevi Krishnamurthy ◽  
Kannappan Panchamoorthy Gopinath ◽  
Ganeshraj Vanathi ◽  
Suresh Ganapathy Shivanirudh
Keyword(s):  
Analytical Techniques ◽  
Cost Effective ◽  
Nano Particles ◽  
Detection Methods ◽  
Spectroscopic Techniques ◽  
Detection Techniques ◽  
Efficient Detection ◽  
High Efficient ◽  
Living Organisms ◽  
Application Fields

Background: Nanoparticle has become an important part of many modern scientific technologies. Also, there are many naturally occurring nanoparticle that play important role in various natural and synthetic processes. Detection of these nanoparticles is expensive and challenging. This review paper explains in detail about various sensor based methods used in detection of nanoparticles. Methodology: Sensor based analytical techniques are more accurate than other techniques. Nanoparticles may occur in air, water, solid surface and human or other living organisms’ physical environments. The detection methods include spectroscopic techniques, electrochemical methods, microcativities and microlasers based detection, optical techniques and many other high sensitive methods. All these methods and their principles are explained in this study. The importance and the ill effects of the nano particles are explained in this article. Further, the detection of a particular single nano particle is also discussed. Conclusions: The detailed comparative analysis of these methods showed that sensor based methods is highly efficient in detection of nanoparticles. The further research in this field may introduce many cost effective and high efficient detection techniques that would revolutionize the medical and other application fields.

An Application of the Polarizable Continnum Model for Obtaining Chalcones Magnetic Properties

2020 ◽  
Vol 12 (7) ◽  
pp. 939-950
Author(s):  
Agnes Jalowitzki Silva ◽  
Thaís F. Giacomello ◽  
Gunar V. da S. Mota ◽  
Antônio M. de J. Chaves ◽  
Fabio L. P. Costa
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Chemical Shift ◽  
Population Distribution ◽  
Chemical Shifts ◽  
Biological Activities ◽  
Geometry Optimization ◽  
Analytical Techniques ◽  
Spectroscopic Techniques ◽  
Nuclear Magnetic

Chalcones exhibit a wide variety of beneficial biological activities. In addition, these compounds include the prevention of diseases related to oxidative stress. The structural characterization of these molecules by means of analytical techniques can become a difficult task due to the complexity of some structures. However, cases of erroneously established natural product structure review are still found in the literature despite recent advances in spectroscopic techniques. Therefore, it is necessary to develop quantum calculation protocols that can aid in the correct structural ascertainment of these compounds. Thus, in this work, we tried to develop a parameterized protocol for calculations of chemical shift of carbon-13 nuclear magnetic resonance, in order to ensure a correct structural determination of polyphenols, with a focus on chalcones. For this, a series of molecules belonging to this class, with complex and varied structural skeletons, reliably elucidated in the literature, was selected and subjected to stochastic conformational searches using the Monte Carlo method and the Merk molecular force filed. The lower energy conformations of each molecule were selected for the geometry optimization step, performed at the mPW1PW91/6-31G(d) level. The chemical shifts of carbon-13 were calculated at the same level of theory, taking into account the population distribution of Boltzmann. The calculations were affected in both liquid phases, using the Polarizable Continuous Model as an implicit solvation model. The results show that the level of theory applied in the liquid phase allows a good reproduction of the experimental data. The application of the scaling factor allows the cancellation of systematic errors, which means that the values of scaled chemical shift are closer to the experimental ones. Thus, the parameterized protocol proved to be an important tool for the structural elucidation of polyphenols by calculations of carbon-13 nuclear magnetic resonance chemical shifts.

Measuring soil organic carbon: which technique and where to from here?

Soil Research ◽  
2015 ◽  
Vol 53 (7) ◽  
pp. 717 ◽  
Author(s):  
Timothy J. Johns ◽  
Michael J. Angove ◽  
Sabine Wilkens
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Time Budget ◽  
Analytical Techniques ◽  
Wet Oxidation ◽  
Spectroscopic Techniques ◽  
Research Needs ◽  
Important Health ◽  
Definition Of ◽  
Selection Of

This review compares and contrasts analytical techniques for the measurement of total soil organic carbon (TOC). Soil TOC is seen to be a highly important health and quality indicator for soils, as well as having the potential to sequester atmospheric carbon. Definition of the form of organic carbon measured by a given method is vital to the selection of appropriate methodology, as well as the understanding of what exactly is being measured. Historically, studies of TOC have ranged from basic measures, such as colour and gravimetric analyses, to dry and wet oxidation techniques. In more recent times, various spectroscopic techniques and the application of remote or mobile approaches have gained prominence. The different techniques, even the oldest ones, may have their place in current research depending on research needs, the available time, budget and access to wider resources. This review provides an overview of the various methods, highlights advantages, limitations and research opportunities and provides an indication of what the method actually measures so that meaningful comparisons can be made.

Spectral Absorption Pattern Detection and Estimation. I. Analytical Techniques

1977 ◽  
Vol 31 (5) ◽  
pp. 404-415 ◽  
Author(s):  
D. R. Morgan
Keyword(s):  
Analytical Techniques ◽  
Electromagnetic Spectrum ◽  
Spectroscopic Techniques ◽  
Unified Theory ◽  
Mathematical Expressions ◽  
Weight Design ◽  
Space Formalism ◽  
Processing Techniques ◽  
Middle Infrared ◽  
Signal Processing Techniques

Spectroscopic techniques have been widely employed in the middle infrared and other regions of the electromagnetic spectrum for the identification and concentration measurement of atmospheric constituents. A principal consideration in such applications is the discrimination of target gas effects from a whole background of interference effects, especially from other known or unknown gases that are present. The primary results presented in this paper concern the development of a unified theory and optimum signal processing techniques that specifically address this problem. Both active and passive, narrowband (laser), and broadband systems are treated simultaneously by adopting a vector space formalism whereby Euclidian coordinates represent appropriate spectral samples. Linear hypothesis testing and LMS estimation theory are then applied in order to derive mathematical expressions for optimum linear weights under various constraints. Both single and multiple targets are considered and a systematic approach to linear weight design is developed.

scholarly journals Recent advances in measurement techniques for atmospheric carbon monoxide and nitrous oxide observations

2019 ◽  
Vol 12 (11) ◽  
pp. 5863-5878 ◽  
Author(s):  
Christoph Zellweger ◽  
Rainer Steinbrecher ◽  
Olivier Laurent ◽  
Haeyoung Lee ◽  
Sumin Kim ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Nitrous Oxide ◽  
Quality Management System ◽  
Measurement Techniques ◽  
Analytical Techniques ◽  
Spectroscopic Techniques ◽  
Near Ir ◽  
Atmospheric Carbon Monoxide ◽  
Ir Spectroscopic ◽  
Improved Accuracy

Abstract. Carbon monoxide (CO) and nitrous oxide (N2O) are two key parameters in the observation of the atmosphere, relevant to air quality and climate change, respectively. For CO, various analytical techniques have been in use over the last few decades. In contrast, N2O was mainly measured using gas chromatography (GC) with an electron capture detector (ECD). In recent years, new spectroscopic methods have become available which are suitable for both CO and N2O. These include infrared (IR) spectroscopic techniques such as cavity ring-down spectroscopy (CRDS), off-axis integrated cavity output spectroscopy (OA-ICOS) and Fourier transform infrared spectroscopy (FTIR). Corresponding instruments became recently commercially available and are increasingly used at atmospheric monitoring stations. We analysed results obtained through performance audits conducted within the framework of the Global Atmosphere Watch (GAW) quality management system of the World Meteorology Organization (WMO). These results reveal that current spectroscopic measurement techniques have clear advantages with respect to data quality objectives compared to more traditional methods for measuring CO and N2O. Further, they allow for a smooth continuation of historic CO and N2O time series. However, special care is required concerning potential water vapour interference on the CO amount fraction reported by near-IR CRDS instruments. This is reflected in the results of parallel measurement campaigns, which clearly indicate that drying the sample air leads to an improved accuracy of CO measurements with such near-IR CRDS instruments.

Uranium determination in groundwater using laser spectroscopy

2014 ◽  
Vol 33 (4) ◽  
Author(s):  
Euo Chang Jung ◽  
Hye-Ryun Cho ◽  
Wansik Cha ◽  
Jong-Ho Park ◽  
Min Hoon Baik
Keyword(s):  
Raman Scattering ◽  
Quantitative Determination ◽  
Calibration Curve ◽  
Limit Of Detection ◽  
Analytical Techniques ◽  
Laser Fluorescence ◽  
Excitation Wavelength ◽  
Spectroscopic Techniques ◽  
Time Resolved

AbstractThe aim of this work is to review the laser-based analytical techniques for the quantitative determination of uranium in aqueous solutions. Among the various types of laser-based analytical techniques, two different spectroscopic techniques based on the measurement of laser-induced luminescence of hexavalent uranium ions [U(VI)] in groundwater are reviewed in detail. In the first technique, called time-resolved laser fluorescence spectroscopy, the time-resolved laser-induced luminescence intensities of U(VI) as a function of uranium concentration are measured to obtain the calibration curve. In the second technique, which is based on the simultaneous measurement of the U(VI) luminescence and Raman scattering of water, the calibration curve is obtained by measuring the ratio of the luminescence intensity of U(VI) to the Raman scattering intensity of water for the quantitative determination of uranium. A limit of detection of 0.03 μg/l was achieved at an excitation wavelength of 266 nm using these laser spectroscopic techniques. The results determined using these techniques are in good agreement with the results determined by inductively coupled plasma mass spectrometry (ICPMS). Thus, these laser-based analytical techniques will be useful to personnel requiring a rapid determination of uranium before the shipment of samples to an accredited laboratory, where relatively intricate and expensive apparatuses, such as ICPMS and radiochemical spectrometry, are used.

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