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Extraction Techniques in Sample Preparation
Sample preparation is the most crucial step in the analytical procedure designed for implementation in any analytical application (food analysis, bionalysis, forensics, toxicology, environmental monitoring etc). It is the limiting factor in chemical analysis since it is time consuming and it can potentially introduce errors. No one can doubt that the best approach would be the direct introduction of the sample to the instrument, however this is rarely feasible. Efficient sample pretreatment is inevitably required as the instrument technology has produced highly sophisticated and sensitive analytical equipment. Hence, the analytical scientists have to develop and apply a suitable sample preparation protocol that ensures that the composition of the sample remains unchanged, no impurities are introduced during handling, all interferences have been left back, the analytes’ concentration is not only at detectable levels, but it can also be quantified precisely and accurately and that the matrix of the sample is compatible with the analytical technique. Extraction techniques are the most powerful tool in hands of the analytical chemists and lab practitioners. Either sorbent based or solvent based, extraction techniques provide the necessary tool that can be used to handle the sample in a way that all information in it can be revealed, all advantages in instrumentation have been exploited to the fullest and the lifetime of the instrument is prolonged in a seamless operation mode.
28 Oct 2020
Inelastic Neutron Scattering
Inelastic neutron scattering (INS) is a spectroscopy based on the energy analysis of neutrons after they have been scattered by a sample. A detected energy transfer can be related to a physical interaction of the corresponding atoms with their environment. An energy transfer of several meVs typically arises from vibrations of atoms. Thus, INS provides an amplitude-of-motion and neutron incoherent cross section weighted phonon density of states. Given the much higher incoherent scattering cross section of hydrogen relative to that of all other elements, INS is particular sensitive to hydrogen based vibrations. The method is widely used in condensed matter physics and solid state chemistry, because the vibrational properties of matter define various physical properties such as the heat capacity. If used as a fingerprint method, INS can be used to characterize chemical bonds both in the bulk as well as on the surface.
30 Oct 2020
Food Colorants Analysis in Foods
Color additives are used extensively in several food products, as to enhance their appearance, and their nutritional properties. They can be defined as “any substance that its intentional addition of which to a food aiming for a technological (including organoleptic) purpose in the manufacture, processing, preparation treatment, packing, packaging, transport or holding of such food results, or may be reasonably expected to result, in it or its by-products becoming a component of the food or otherwise affecting the characteristics of such foods”. Thus, hereby they are presented all the late advancements related to existing analytical methods and sample preparation methodologies, for their determination and quantification in food matrices.Furthermore, all these advancements are connected to general information about the existing natural or synthetic food colorants, along with legislative information and toxicological aspects, in order to support the importance and the need of appropriate analytical methodologies.
12 Jan 2021
Dendrimer a beautiful greek word in magic of chemistry
Chemistry is the magic science that gives a good reason in people to follow it. For me as a greek chemist it's very interesting that in science a lot of words came from my native language. One of this words is the word dendrimer that came from synthesis of two grre words. In this article I want to speak about this and to express, that the interesting, is that the dendrimer didn't found it in Greece, but take a greek name.
29 Dec 2021
Laboratory of Analytical Chemistry
The Laboratory of Analytical Chemistry was established in 1963 and is part of the Department of Physical, Analytical and Environmental Chemistry of the School of Chemistry in the Faculty of Sciences of Aristotle University of Thessaloniki (AUTh). Today the Laboratory has seven Faculty members: Six Professors (Aristidis Anthemidis, Stella Girousi, Victoria Samanidou, George Theodoridis, George Zachariadis, Anastasia-Stella Zotou), and two Assistant Professors (Paraskevas Tzanavaras and George Tsogkas). Its function is also supported by 1 member of the Technical Staff (Foteini Zougrou, MSc Chemist). The main subject of the Laboratory's teaching and research is analytical chemistry, namely the development, validation and application of new analytical methods, as well as the exploration of new instrumental techniques and innovative materials used in chemical analysis. Within the framework of the educational services provided by the Laboratory, a number of courses are offered in the undergraduate and postgraduate curricula. Besides the students of the Department of Chemistry, students of other departments of AUTh are also trained. The main research fields served by the faculty members of the Laboratory of Analytical Chemistry, include: SEPARATION AND HYPHENATED ANALYTICAL TECHNIQUES SPECTROSCOPIC, AUTOMATED AND MULTIELEMENTAL TECHNIQUES ELECTROANALYTICAL TECHNIQUES, SENSORS AND BIOSENSORS MODERN SAMPLE PREPARATION TECHNIQUES AND INNOVATIVE MATERIALS
29 Oct 2020
Colorimetric analysis has become of great importance in recent years to improve the operationalization of plasmonic-based biosensors. The unique properties of nanomaterials have enabled the development of a variety of plasmonics applications on the basis of the colorimetric sensing provided by metal nanoparticles. In particular, the extinction of localized surface plasmon resonance (LSPR) in the visible range has permitted the exploitation of LSPR colorimetric-based biosensors as powerful tools for clinical diagnostics and drug monitoring. This review summarizes recent progress in the biochemical monitoring of clinical biomarkers by ultrasensitive plasmonic colorimetric strategies according to the distance- or the morphology/size-dependent sensing modes. Colorimetric analysis has become of great importance in recent years to improve the operationalization of plasmonic-based biosensors. The unique properties of nanomaterials have enabled the development of a variety of plasmonics applications on the basis of the colorimetric sensing provided by metal nanoparticles. In particular, the extinction of localized surface plasmon resonance (LSPR) in the visible range has permitted the exploitation of LSPR colorimetric-based biosensors as powerful tools for clinical diagnostics and drug monitoring. This review summarizes recent progress in the biochemical monitoring of clinical biomarkers by ultrasensitive plasmonic colorimetric strategies according to the distance- or the morphology/size-dependent sensing modes.
03 Nov 2020
Laser Absorption Spectroscopy
Laser absorption spectroscopy (LAS) is an absorption spectroscopic method that employs a laser as the light source and measures the chemical concentration based on detection of a variation of laser beam intensity after transmission along the optical path.
10 Sep 2020
Capillary-Driven Flow Microfluidics
Point-of-care (POC) or near-patient testing allows clinicians to accurately achieve real-time diagnostic results performed at or near to the patient site. The outlook of POC devices is to provide quicker analyses that can lead to well-informed clinical decisions and hence improve the health of patients at the point-of-need. Microfluidics plays an important role in the development of POC devices. However, requirements of handling expertise, pumping systems and complex fluidic controls make the technology unaffordable to the current healthcare systems in the world. In recent years, capillary-driven flow microfluidics has emerged as an attractive microfluidic-based technology to overcome these limitations by offering robust, cost-effective and simple-to-operate devices. The internal wall of the microchannels can be pre-coated with reagents, and by merely dipping the device into the patient sample, the sample can be loaded into the microchannel driven by capillary forces and can be detected via handheld or smartphone-based detectors. The capabilities of capillary-driven flow devices have not been fully exploited in developing POC diagnostics, especially for antimicrobial resistance studies in clinical settings. The purpose of this review is to open up this field of microfluidics to the ever-expanding microfluidic-based scientific community.
24 Jul 2020
Fucoxanthin Extracted from Brown Algae
The scientific community has corroborated the numerous beneficial activities of fucoxanthin, such as its antioxidant, anti-inflammatory, anticancer or neuroprotective effects, among others. These properties have attracted the attention of nutraceutical, cosmetic and pharmacological industries, giving rise to various possible applications. Fucoxanthin may be chemically produced, but the extraction from natural sources is considered more cost-effective, efficient and eco-friendly. Thus, identifying suitable sources of this compound and giving a general overview of efficient extraction, quantification, purification and stabilization studies is of great importance for the future production and commercialization of fucoxanthin. The entry describes the potential applications of fucoxanthin pigment. Its production must face several challenges since its chemical synthesis represents a complex process which is not efficient and the extraction method from marine organisms has been not standardized. The main characteristic of a profitable product is to be obtained by using simple, fast, and based on low-cost technologies. This work provides an overview of different extraction conditions that may help in the standardization of the process, especially important at an industrial level. Therefore, the main aim of this work has been to underline the best algae species in terms of fucoxanthin production and the most promising extraction and purification methods, while offering a complete panorama of the described bioactivities of fucoxanthin which includes bioavailability, administration via, doses and stability of the molecule under different conditions.
06 Feb 2021
Victoria F. Samanidou
Dr. Victoria Samanidou is Full Professor in the Laboratory of Analytical Chemistry in the School of Chemistry of Aristotle University of Thessaloniki, Greece. She was born, in Thessaloniki, Greece, on the 11th of January 1963. Dr Samanidou has authored and co-authored more than 170 original research articles in peer reviewed journals and 45 reviews and 50 chapters in scientific books, with H-index 36 (Scopus February 2020, http://orcid.org/0000-0002-8493-1106, Scopus Author ID 7003896015) and ca 3500 citations. She is member of editorial board of more than 10 scientific journals and she has reviewed ca 550 manuscripts in more than 100 scientific journals. She has served as Academic Editor for Separations mdpi, as Regional editor in Current Analytical Chemistry, Since December 2015 Dr Samanidou has been elected as President of the Steering Committee of the Division of Central and Western Macedonia of the Greek Chemists’ Association. In November 2018 she has been reelected to serve at the same leading position for 3 more years. A milestone in her career was in 2016, when she was included in top 50 power list of women in Analytical Science, as proposed by Texere Publishers.
29 Oct 2020
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