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Topic Review
Deep Eutectic Solvents
Deep eutectic solvents (DESs), were introduced in 2001 as an alternative to ILs. These showed a stronger ecofriendly profile, with easier and cheaper production, while having similar properties. DESs contain large, asymmetrical ions that have low lattice energy and, thus, low melting points. They are often acquired by the complexation of a quaternary ammonium salt with a metal salt or hydrogen bond donor (HBD). The charge delocalization occurring through hydrogen bonding between, for instance a halide ion and the hydrogen-donor moiety, is responsible for the decrease in the melting point of the mixture, in relation to the melting points of the individual components. Since 2001, many scientists around the globe pursed the utilization of DESs and published a variety of studies. The use of DESs in analytical microextraction techniques is on the rise, due to the many benefits they provide, such as lower cost and easier synthesis than ILs and an environmentally friendly profile, because of the low toxicity reported, although they need further investigation. To this day, the number of HBAs and HBDs is quite limited, so more studies ought to be carried out to present a plethora of DESs available for use. Moreover, DESs are not commercially available yet, substantially affecting and further limiting their usage for routine analyses in industrial or certified laboratories. The extraordinary high relative recoveries, selectivity, low LODs and decent repeatability they offer, render them appropriate for the determination and quantification of lots of compounds in either simple or complex matrices. As seen, most applications regard liquid phase microextractions rather than solid phase microextractions, because of their liquid nature, as it is simpler to use them as supporting solid adsorbents. The fact that the sample preparation of complicated matrices is of high interest makes them ideal for the research. Hopefully, DESs will be available for purchase in the foreseeable future and will replace organic solvents in some analytical methods commonly used nowadays, while more studies are carried out about their properties. Our aim in this review will be towards the use of DESs in analytical extraction and microextraction techniques, while briefly presenting some frequently used DESs, their synthesis methods and their properties. The ever-increasing use of deep eutectic solvents (DES) in microextraction techniques will be discussed, focusing on the reasons needed to replace conventional extraction techniques with greener approaches that follow the principles of green analytical chemistry.
  • 2.8K
  • 10 Feb 2021
Topic Review
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.
  • 2.7K
  • 06 Feb 2021
Topic Review
Spray Drying for Oils Encapsulation
This is a entry focused on the application of spray drying technology for the edible oils encapsulation. This entry covered most of the relevant works have done recently on the encapsulation of oils by spray drying. The factors affecting the process of encapsulation and the application in food with the properties of the final product.The application of the spray drying technique in the food industry for the production of a broad range of ingredients has become highly desirable compared to other drying techniques. Recently, the spray drying technique has been applied extensively for the production of functional foods, pharmaceuticals and nutraceuticals. Encapsulation using spray drying is highly preferred due to economic advantages compared to other encapsulation methods. Encapsulation of oils using the spray drying technique is carried out in order to enhance the handling properties of the products and to improve oxidation stability by protecting the bioactive compounds. Encapsulation of oils involves several parameters—including inlet and outlet temperatures, total solids, and the type of wall materials—that significantly affect the quality of final product.
  • 2.6K
  • 19 Apr 2022
Topic Review
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. 
  • 2.5K
  • 29 Dec 2021
Topic Review
Detection of Beta-Glucan
This entry provides a comprehensive review of the current literature about biological properties and available methods for the detection of beta-glucans. It shares the experience of the Nanotechnology Characterization Laboratory with the detection of beta-glucans in nanotechnology-based drug products. This entry summarizes and discusses five different approaches currently applied for the data interpretation of beta-glucan tests with respect to the acceptability (or lack thereof) of the beta-glucan levels in pharmaceutical products.
  • 2.5K
  • 03 Nov 2020
Topic Review
Methods for Determination of Lipophilicity
Lipophilicity is one of many parameters involved in the biological activity of drugs, as it affects their pharmacokinetic and pharmacodynamic behavior. Generally, lipophilicity is assessed by the partition coefficient of a compound between a nonpolar phase (n-octanol) and an aqueous phase (water), expressed as P (partition coefficient) or as its decimal logarithm (Log P). The gold standard method for the experimental determination of Log P is the shake-flask method.
  • 2.4K
  • 25 Aug 2022
Topic Review
Ring Expansion and Ring Contraction
Ring expansion and ring contraction reactions in the course of organic synthesis refer to a set of reactions which can lead to the expansion or contraction of an existing ring. This often makes it possible to access structures that would be difficult if not impossible to synthesise with single cyclization reactions. Ring expansions are valuable because they allow access to larger systems that are difficult to synthesize through a single cyclization due to the slow rate of formation. Ring contractions are useful for making smaller, more strained rings from larger rings. Expansions are classified by the mechanism of expansion and the atom(s) added; contractions are characterized simply by the reactive intermediate which performs the contraction.
  • 2.3K
  • 01 Dec 2022
Topic Review
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
  • 2.3K
  • 29 Oct 2020
Topic Review
Molecular Imprinting
Molecular imprinting is a technique for creating artificial recognition sites on polymer matrices that complement the template in terms of size, shape, and spatial arrangement of functional groups. The main advantage of Molecularly Imprinted Polymers (MIP) as the polymer for use with a molecular imprinting technique is that they have high selectivity and affinity for the target molecules used in the molding process. 
  • 2.2K
  • 30 Nov 2021
Topic Review
Sensors for Hydrogen Peroxide Detection
 Hydrogen peroxide (H2O2) is a key molecule in numerous physiological, industrial, and environmental processes. H2O2 is monitored using various methods like colorimetry, luminescence, fluorescence, and electrochemical methods. Here, we aim to provide a comprehensive review of solid state sensors to monitor H2O2. The review covers three categories of sensors: chemiresistive, conductometric, and field effect transistors. A brief description of the sensing mechanisms of these sensors has been provided. All three sensor types are evaluated based on the sensing parameters like sensitivity, limit of detection, measuring range and response time. We highlight those sensors which have advanced the field by using innovative materials or sensor fabrication techniques. Finally, we discuss the limitations of current solid state sensors and the future directions for research and development in this exciting area. 
  • 2.1K
  • 30 Jan 2021
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