Various chromatography methods

Ebook "Russian contributions to analytical chemistry" offers a unique perspective and novel information on the significant contributions of Russian scientists to analytical chemistry and chemical analysis. Written by the Editor-in-Chief of the Journal of Analytical Chemistry, it discusses various examples of new methods and approaches originating in Russia, such as chromatography, electrothermal atomic absorption spectrometry, Kumakhov X-ray optics, the Spolský effect in fluorescent analysis and important innovations in mass spectrometry, which are already widely used.

165p tracanhphuonghoa1007 22-04-2024 7 3   Download

Ebook "Modified cyclodextrins for chiral separation" offers a review of the latest advances in developing modified cyclodextrins as chiral selectors for various chromatographic and electromigration techniques. Over the years, many descriptions of chiral separation have appeared in academic journals and books, but most of them have been devoted to either the development of analytical methods and protocols or the summary of different chiral selectors, including cyclodextrins for chiral separation applications.

265p coduathanh1122 27-03-2024 2 1   Download

Ebook "Characterization and authentication of olive and other vegetable oils: New analytical methods" presents new methods for the characterization of vegetable oils, with focus in olive oil, according to geographical and botanical origin, genetic variety and other issues influencing product quality. A wide variety of analytical techniques have been employed, such as various chromatographic techniques (different gas and liquid chromatography methods), an electronic nose, infrared spectroscopy and expert-panel evaluation.

229p coduathanh1122 27-03-2024 6 1   Download

Ebook "The electron capture detector and the study of reactions with thermal electrons" describes the general theory and practice of using the Electron Capture Detector (ECD) to study reactions of thermal electrons with molecules. It reviews electron affinities and thermodynamic and kinetic parameters of atoms, small molecules, and large organic molecules obtained by using various methods.

412p coduathanh1122 27-03-2024 5 1   Download

Allium ascalonicum, the tunic of which holds various bioactive compounds including including quercetin - a potent flavonoid, is renowned for its medicinal properties. This study presents the development and validation of a High-Performance Liquid Chromatography (HPLC) method for quantifying quercetin in Allium ascalonicum tunic.

6p vigojek 02-02-2024 3 2   Download

This study aimed to develop a method for measuring eight alkenylbenzenes (eugenol, methyl eugenol, acetyl eugenol, trans-isoeugenol, safrole, estragole, myristicin and trans-anethole) in various spices using gas chromatography highresolution mass spectrometry (GC-HRMS) with a simple ultrasonic vibration sample extraction method.

13p vigojek 02-02-2024 2 1   Download

Pesticides are extensively used to control pests and destroy weeds, so they are ubiquitous contaminants accumulating in our environment. Such residues can be determined by using various chemical methods among which the most common are based on gas chromatography or liquid chromatography.

7p visnape 30-01-2023 12 4   Download

Headspace in-tube extraction (HS-ITEX) and solid phase microextraction (HS-SPME) sampling, followed by gas chromatography-mass spectrometry (GC–MS), are widely used to analyze volatile compounds in various food matrices.

11p viginny 23-12-2022 13 3   Download

The use of scanning gradients can significantly reduce method-development time in reversed-phase liquid chromatography. However, there is no consensus on how they can best be used. In the present work we set out to systematically investigate various factors and to formulate guidelines.

13p viginny 23-12-2022 10 3   Download

A new, rapid, and sensitive gas chromatography–mass spectrometry (GC-MS) method was developed for the determination of ezetimibe (EZE) in human plasma. EZE was derivatized prior to GC-MS analysis. Various derivatization techniques such as acetylation, methylation, and silylation were tried. EZE was extracted from plasma with high recovery (94.39%–97.57%) using methyl tertbutyl ether and carbonate buffer (pH 9). Chromatographic conditions were optimized using chemometric methods.

12p langthannam 29-12-2021 10 0   Download

Electrochemical properties of disulfiram, representative of highly significant bioactive compounds, were studied with a cyclic renewable silver amalgam film electrode (Hg(Ag)FE) using square wave cathodic stripping voltammetry (SWCSV). The influence of various factors such as pH, buffer concentration, buffer composition, and SWCSV parameters on current response was investigated. The applicability of the developed method was tested in the determination of disulfiram in the commercial formulation Anticol.

9p langthannam 29-12-2021 15 0   Download

An efficient and inexpensive monolithic stationary phase (PHEMA-HA) has been prepared through an easy process comprising addition of humic acid (HA) to a mixture of 2-hydroxyethyl methacrylate (HEMA) and N,N’- methylenebisacrylamide (MBAAm) and subsequent radical-polymerization at –20 ◦ C. The prepared monolithic material was characterized in terms of various techniques and methods such as elemental analysis, FTIR spectroscopy, scanning electron microscopy, mercury porosimetry, hydrolytic stability tests, pHpzc measurements, water-holding capacity, and water permeability.

16p tudichquannguyet 29-11-2021 10 1   Download

Isoquercitrin is a flavonoid chemical compound that can be extracted from different plant species such as Mangifera indica (mango), Rheum nobile, Annona squamosal, Camellia sinensis (tea), and coriander (Coriandrum sativum L.). It possesses various biological activities such as the prevention of thromboembolism and has anticancer, antiinflammatory, and antifatigue activities. Therefore, there is a critical need to elucidate and predict the qualitative and quantitative properties of this phytochemical compound using the high performance liquid chromatography (HPLC) technique.

13p tudichquannguyet 29-11-2021 12 1   Download

Laggera tomentosa Sch. Bip. ex Oliv. et Hiern (Asteraceae), an endemic Ethiopian medicinal plant, is traditionally used to treat various ailments. Previously, the chemical constituents of the essential oil (EO) of its leaves and inflorescence were documented. However, no data about the chemical compositions of other parts of the EOs of the plant have been reported to date. Moreover, there are no previous biological activity reports on any parts of the EOs of this plant.

10p tudichquannguyet 29-11-2021 13 1   Download

The prostate-specific membrane antigen (PSMA) represents an ideal biomarker for molecular imaging. Various PSMAtargeted radioligands are available for prostate cancer imaging. In this study, labeling of PSMA I&T with 68Ga, as well as validation of the radiochemical purity of the synthesis product by reverse phase radio high-performance liquid chromatography (HPLC) method are intended. Since the standard procedure for the quality control (QC) was not available, definition of chemical and radiochemical purity of 68Ga-PSMA I&T was carried out according to the Q2 (R1) ICH guideline.

9p tudichquannguyet 29-11-2021 10 0   Download

Tracing stable isotopes, such as 13C using various mass spectrometry (MS) methods provides a valuable information necessary for the study of biochemical processes in cells. However, extracting such information requires special care, such as a correction for naturally occurring isotopes, or overlapping mass spectra of various components of the cell culture medium.

9p vioklahoma2711 19-11-2020 1 1   Download

A method of reverse phase-high performance liquid chromatography (HPLC) was standardized and developed coupled with modified UV-VIS detection system was standardized for simultaneous determination of residues of imidacloprid, carbofuran, chlorantraniliprole, fipronil, malathion, chloropyriphos and cypermethrin in rice grains. Extraction and clean-up process was done by modified QuEChERS method.

6p gaocaolon5 14-06-2020 8 2   Download

Vandetanib (VNT) is a new oral tyrosine kinase inhibitor that acts mainly by inhibiting vascular endothelial growth factor receptor (VEGFR). Fast, specific, sensitive and validated LC–MS/MS was established for the determination of VNT in two various matrices including rat liver microsome (RLMs) and human plasma.

8p vijiraiya2711 27-05-2020 15 1   Download

Bridelia micrantha commonly known as coastal golden leaf is a member of the family Phyllanthaceae. In preliminary studies, nine fractions, named F1- F9, were obtained by fractionating the crude methanol extract of the stem bark of Bridelia micrantha using column chromatographic techniques. The F6 fraction was found to be the most active when tested for the antibacterial activity. This study is thus aimed at investigating the effect of fractionation on antibacterial activity of F6 fraction.

18p nguaconbaynhay3 07-02-2020 19 0   Download

Seafood is the most significant perishable commodity. Decomposition of seafood, especially during storage at elevated temperatures (48˚C), various amounts of selected biogenic amines is usually produced, depending on the fish species. Most common biogenic amines in seafood associated with spoilage are histamine, tyramine, putrescine and cadaverine which are formed by bacteria that decarboxylases the corresponding free amino acids. Histamine is known as a biogenic amine which is low molecular weight and possesses biological activity.

12p kequaidan2 13-12-2019 29 1   Download