نتایج جستجو برای: total polar compounds

تعداد نتایج: 1047019  

2001
Mingliang Ye Hanfa Zou Liang Kong Zhengdeng Lei Renan Wu Jianyi Ni

and Yan (5) reported that they successfully separated high polarity explosives using CEC with nonporous C18-coated material and a mobile phase with a low concentration of organic modifier and SDS added to the mobile phase to increase the wettability of the particle surface. Zhang and colleagues (9) also reported that very polar compounds could be separated by mixed-packing CEC with a stationary...

The electronic structure and spectra of 3-formylchromone and some of its derivatives are investigated using TD-DFT/B3LYB/6-311G (d, p) level of theory. The results of calculations show that all the studied compounds 1–6 are planar, as indicated from the dihedral angles. The electronic absorption spectra of the studied compounds are recorded in the UV-Vis region, in both ethanol (as polar solven...

Journal: :Food chemistry 2013
Ibrahim M Abu-Reidah David Arráez-Román Antonio Segura-Carretero Alberto Fernández-Gutiérrez

The aim of this work was to characterise the phenolic compounds in artichoke (hearts) by using HPLC coupled to DAD-ESI-QTOF-MS, which proved useful in characterising 61 phenolic and other polar compounds. Notably, of the 61 compounds characterised, 34 new phenolic compounds with their isomers have been tentatively characterised in artichoke for the first time, namely: 3 hydroxybenzoic acids, 17...

Journal: :The Analyst 2002
Judith A Brisbin Joseph A Caruso

A variety of extraction procedures were evaluated for the extraction of arsenic and other analytes from lobster tissue samples using inductively coupled plasma mass spectrometry (ICP-MS) detection. Soxhlet, room temperature mixing, sonication, microwave assisted, supercritical carbon dioxide and subcritical water extractions were evaluated for a variety of solvent systems and optimum conditions...

A. Sami, H. Ayub, M. Awan, N. Khalid, W. Nazir,

Background: Street foods have gained popularity around the world in the past few decades. The current study was carried out in order to quantitative analysis of used cooking oils by Street Food Vendors (SFVs) of Lahore, Pakistan. Methods: Fifty samples of cooking oil used by SFVs were collected. Also, a questionnaire was designed for qualitative assessment that revealed maximum vendors used ve...

Journal: :Applied sciences 2023

Growing consumer demand for high-quality products coupled with minimally processed and a minor use of synthetic food additives have increased the need to search new sources natural antimicrobials ensure product safety. This study aimed evaluate antimicrobial activity extracts from brown algae Ericaria selaginoides against Bacillus cereus in typical Catalan fresh cheese (“mató”) by means challen...

Journal: :Journal of AOAC International 2015
Maki Kanda Takayuki Nakajima Hiroshi Hayashi Tsuneo Hashimoto Setsuko Kanai Chieko Nagano Yoko Matsushima Yukinari Tateishi Soichi Yoshikawa Yumi Tsuruoka Takeo Sasamoto Ichiro Takano

Residues of 37 polar veterinary drugs belonging to six families (quinolones, tetracyclines, macrolides, lincosamides, sulfonamides, and others) in livestock and fishery products were determined using a validated LC-MS/MS method. There were two key points in sample preparation. First, extraction was performed with two solutions of different polarity. Highly polar compounds were initially extract...

Journal: :Journal of chromatography. A 2014
Jessica A Sagona James E Dukett Harmonie A Hawley Monica A Mazurek

Cloud water samples from Whiteface Mountain, NY were used to develop a combined sampling and gas chromatography-mass spectrometric (GCMS) protocol for evaluating the complex mixture of highly polar organic compounds (HPOC) present in this atmospheric medium. Specific HPOC of interest were mono- and di keto-acids which are thought to originate from photochemical reactions of volatile unsaturated...

Journal: :Environmental science & technology 2005
Daniel U Pedersen John L Durant Koli Taghizadeh Harold F Hemond Arthur L Lafleur Glen R Cass

Few reports have characterized mutagenic compounds in respirable airborne particles (<2.5 micrometers in diameter; PM2.5) collected at different sites on a regional scale (hundreds of km). Previously, we reported differences in the human (h1A1v2) cell mutagenicity of whole and fractionated organic extracts of PM2.5 samples collected in Boston, MA, Rochester, NY, and Quabbin Reservoir, a rural s...

Journal: :Analytical chemistry 2013
Xiaojiang Xie Gastón A Crespo Eric Bakker

We propose here a new class of fluorescent H(+) turn-on oxazinoindoline (Ox) dyes as chromoionophores suitable for the development of polymeric ion-selective membranes. Through rational design, oxazinoindolines with varying basicities and tunable absorption bands that extend to the near-infrared region were prepared. The basicities of the compounds were evaluated by potentiometry and fluorescen...

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