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Micellar Liquid Chromatography

Ning Li, N M El Zahar, Jack G Saad, Erik R E van der Hage, Michael G Bartlett
Alkylamines are commonly used to improve both chromatographic and mass spectral performance of electrospray ionization liquid chromatography mass spectrometry based methods for the analysis of oligonucleotides. Recently several new alkylamines have been introduced to enhance the electrospray mass spectral response for oligonucleotides; however, the chromatographic properties of these new alkylamines have not been rigorously assessed. We have investigated the retention, peak width, resolution and general chromatographic performance of fifteen different alkylamines for the separation of a model DNA, RNA and an antisense therapeutic oligonucleotide...
October 25, 2018: Journal of Chromatography. A
Hiroshi Habe, Toshiaki Taira, Tomohiro Imura
Bacillus licheniformis NBRC 104464 produces a cyclic lipopeptide different from surfactin. After we performed liquid chromatography fractionation and purification, we used structural analyses to identify the cyclic lipopeptide as lichenysin. Surface tension measurements of lichenysin sodium salt in water yielded a critical micelle concentration (CMC) of 1.0×10-5 M. The surface tension at the CMC was 28.9 mN/m. Comparative analysis of Ca2+ -influenced micellar aggregation of lichenysin and surfactin revealed that the formation rate of the lichenysin-Ca2+ complex aggregate remained low up to a [Ca2+ ]/[lichenysin] molar ratio of 80, whereas the surfactin-Ca2+ complex formed micellar aggregates at the same molar ratio...
2018: Journal of Oleo Science
Mirjam Kummer, Nela Šestáková, Regula Theurillat, Uyen Huynh-Do, Andrea Endimiani, Parham Sendi, Wolfgang Thormann
Cefepime monitoring in urine by micellar electrokinetic capillary chromatography with UV detection and liquid chromatography coupled to mass spectrometry via electrospray ionization is described. For micellar electrokinetic capillary chromatography, sample preparation comprised urine dilution and dodecyl-sulfate protein precipitation at pH 4.5, whereas diluted urines were analyzed in the other assay. Both approaches provided suitable conditions for cefepime analysis in urines of healthy volunteers that were spiked with cefepime...
November 2018: Journal of Separation Science
Feng Li, Huixia Zhang, Miao He, Jinhui Liao, Nianhang Chen, Yan Li, Simon Zhou, Maria Palmisano, Alex Yu, Manjunath P Pai, Hebao Yuan, Duxin Sun
Previous studies have shown that different paclitaxel formulations produce distinct anticancer efficacy and safety profiles in animals and humans. This study aimed to investigate the distinct pharmacokinetics and tissue distribution of various nanoformulations of paclitaxel, which may translate into potential differences in safety and efficacy. Four nanoparticle formulations ( nab-paclitaxel, mouse albumin nab-paclitaxel [m -nab-paclitaxel], micellar paclitaxel, and polymeric nanoparticle paclitaxel) as well as solvent-based paclitaxel were intravenously administered to mice...
October 1, 2018: Molecular Pharmaceutics
Federica Ianni, Lucia Pucciarini, Andrea Carotti, Serena Natalini, Gulnara Z Raskildina, Roccaldo Sardella, Benedetto Natalini
Chiral ligand-exchange chromatography is one of the elective strategies for the direct enantioresolution of small chelating compounds: amino acids, diamines, amino alcohols, diols, small peptides, etc. Unlike other methods, the interaction between chiral selector and analyte enantiomers is mediated by a cation, thus producing diastereomeric ternary complexes. Two main approaches are conventionally applied in chiral ligand-exchange chromatography. The first relies upon chiral stationary phases where the chiral selector is either covalently immobilized or physically adsorbed onto suitable packing materials (coated phases)...
August 27, 2018: Journal of Separation Science
Xuanxuan Wang, Xiao Li, Yuxiu Xiao
A novel hexafluoroisopropanol (HFIP)-octanol supramolecular solvent (SUPRAS) based dispersive liquid-liquid microextraction (DLLME) method was developed for the determination of 2,6-dimethylaniline (2,6-DMA) in lidocaine hydrochloride injection coupled with high performance liquid chromatography-ultraviolet detection (HPLC-UV). n -Octanol was selected as extraction solvent while HFIP was served as dispersing agent, self-assembly inducer of n -octanol as well as density-regulating agent of n -octanol. The HFIP-octanol SUPRAS displays reverse micellar aggregate structures (2-6 μm) with hydrophilic inner cores and is located in the bottom phase of the system after phase separation, which not only facilitates the efficient extraction and enrichment of polar 2,6-DMA, but also simplifies the extraction process...
March 8, 2018: Se Pu, Chinese Journal of Chromatography
Juan Peris-Vicente, Jesús Javier Iborra Millet, Jaume Albiol-Chiva, Samuel Carda-Broch, Josep Esteve-Romero
BACKGROUND: Micellar liquid chromatography - fluorescence detection was used to determine the antibiotics flumequine, marbofloxacin, difloxacin and sarafloxacin in porcine, bovine, poultry, ovine, caprine, rabbit and equine meat, to verify their compliance with the EU Regulation 37/2010 about the occurrence of veterinary drugs in food. RESULTS: The analytes were isolated from matrix by ultrasonication-assisted leaching in a micellar solution, and the supernatant was filtered and directly injected...
August 17, 2018: Journal of the Science of Food and Agriculture
Dina S Shokry, Laura J Waters, Gareth M B Parkes, John C Mitchell
Micellar liquid chromatography is a popular method used in the determination of a compound's lipophilicity. This study describes the use of the obtained micelle-water partition coefficient (log Pmw ) by such a method in the prediction of human intestinal absorption (HIA). As a result of the close resemblance of the novel composition of the micellar mobile phase to that of physiological intestinal fluid, prediction was deemed to be highly successful. The unique micellar mobile phase consisted of a mixed micellar mixture of lecithin and six bile salts, i...
July 30, 2018: Biomedical Chromatography: BMC
Isabel Cristina Celerino de Moraes Porto, Dayse Chaves Cardoso de Almeida, Gabriela Vasconcelos Calheiros de Oliveira Costa, Tayná Stéphanie Sampaio Donato, Letícia Moreira Nunes, Ticiano Gomes do Nascimento, José Marcos Dos Santos Oliveira, Carolina Batista da Silva, Natanael Barbosa Dos Santos, Maria Luísa de Alencar E Silva Leite, Irinaldo Diniz Basílio-Júnior, Camila Braga Dornelas, Pierre Barnabé Escodro, Eduardo Jorge da Silva Fonseca, Regianne Umeko Kamiya
BACKGROUND: Propolis is a natural substance produced by bees and is known to have antimicrobial activity. Our aim was to evaluate the antimicrobial effect of micellar nanocomposites loaded with an ethyl acetate extract of Brazilian red propolis as a cavity cleaning agent and its influence on the color and microtensile bond strength (μTBS) of the dentin/resin interface. METHODS: An ultra-performance liquid chromatography coupled with a diode array detector (UPLC-DAD) assay was used to determine the flavonoids and isoflavones present in an ethyl acetate extract of Brazilian red propolis (EARP) and micellar nanocomposites loaded with EARP (MNRP)...
July 18, 2018: BMC Complementary and Alternative Medicine
Fawzia Ibrahim, Asmaa Kamal El-Deen, Kuniyoshi Shimizu
In the present study, we compare the performance of two reversed-phase liquid chromatographic approaches using different eluents either conventional hydro-organic eluent or micellar one for simultaneous estimation of hydrocortisone acetate and pramoxine hydrochloride in presence of their degradants and process-related impurities; hydrocortisone and 4-butoxyphenol, respectively. For conventional reversed-phase liquid chromatography (RPLC), separation of the studied compounds was completed on an Inertsil ODS 3-C18 column (150 mm × 4...
July 2018: Journal of Food and Drug Analysis
Sarah Nasser, Paulo De Sa Peixoto, Anne Moreau, Thomas Croguennec, Fabrice Bray, Christian Rolando, Frédéric J Tessier, Alain Hédoux, Guillaume Delaplace
During storage, a series of changes occur for dairy powders, such as protein lactosylation and the formation of Maillard reaction products (MRPs), leading to powder browning and an increase of insoluble matter. The kinetics of protein lactosylation and MRP formation are influenced by the lactose content of the dairy powder. However, the influence of lactose in the formation of insoluble matter and its role in the underlying mechanisms is still a subject of speculation. In this study, we aim to investigate the role of lactose in the formation of insoluble matter in a more comprehensive way than the existing literature...
October 3, 2018: Journal of Agricultural and Food Chemistry
Ester Peris-García, Jorge Rodríguez-Martínez, Juan J Baeza-Baeza, María Celia García-Alvarez-Coque, María José Ruiz-Angel
Most reports in reversed-phase liquid chromatography (RPLC) with micellar mobile phases make use of the anionic sodium dodecyl sulfate. This surfactant masks efficiently the silanol groups that are the origin of the poor efficiencies and tailing peaks observed for basic compounds in conventional RPLC. However, it has the handicap of yielding excessive retention, which forces the addition of an organic solvent to reduce the retention times to practical values. Other surfactants, such as the non-ionic polyoxyethylene(23)lauryl ether (Brij-35), are rarely used...
June 19, 2018: Analytical and Bioanalytical Chemistry
Jessica Fiori, Benedetta Pasquini, Claudia Caprini, Serena Orlandini, Sandra Furlanetto, Roberto Gotti
Monomeric catechins are important compounds in green tea accounting for potential bioactivity against a wide range of diseases. Besides catechins, l-Theanine (γ-glutamylethylamide), a characteristic amino acid in tea leaves, has become a further focus of the phytochemical research for the reported beneficial effects mainly on cognitive performance, emotional state and sleep quality. In the present study has been developed a CD-MEKC method based on sodium dodecyl sulfate (SDS) and Heptakis (2,6-di-O-methyl)-β-cyclodextrin for the separation of six major green tea catechins and enantiomers of theanine...
August 10, 2018: Journal of Chromatography. A
F Belal, F Ibrahim, Z A Sheribah, H Alaa
A method based on micellar liquid chromatography to quantify levodopa, carbidopa and entacapone in plasma is reported. The sample pretreatment was a simple dilution in a pure micellar solution then filtration and direct injection, without requiring extraction or purification steps. The three drugs were resolved from the matrix in 7 min, using an aqueous solution of 0.1 M sodium dodecyl sulphate-10% n-propanol-0.3 tiethylamine, adjusted at pH 2.8 with 0.02 M orthophosphoric acid as mobile phase, running under isocratic mode at 1...
August 1, 2018: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
Samereh Ranjbar Bandforuzi, Mohammad Reza Hadjmohammadi
The extraction of phthalate esters (PEs) from aqueous matrices using two-phase solvent bar microextraction by organic micellar phase was investigated. A short hollow fiber immobilized with reverse micelles of Brij 35 surfactant in 1-octanol was served as the solvent bar for microextraction. Experimental results show that the extraction efficiency were much higher using two-phase solvent bar microextraction based on non-ionic surfactant than conventional two-phase solvent bar microextraction because of a positive effect of surfactant-containing extraction phase in promoting the partition process by non-ionic intermolecular forces such as polar and hydrophobicity interactions...
August 3, 2018: Journal of Chromatography. A
Qing Yang, Beibei Chen, Man He, Bin Hu
A rapid, simple, and effective method has been developed for the determination of seven triazine herbicides (terbutryn, prometryn, ametryn, prometon, propazine, atrazine, simazine) by coupling off-line hollow fiber liquid liquid liquid microextraction (HF-LLLME) with on-line sweeping micellar electrokinetic chromatography (sweeping-MEKC). In HF-LLLME, seven target triazines in hydrophobic form were extracted from the sample solution into decane impregnated in the pores of the hollow fiber, and then back-extracted into 1 mol L-1 H3 PO4 inside the hollow fiber lumen...
August 15, 2018: Talanta
Natalia Miękus, Ilona Olędzka, Natalia Kossakowska, Alina Plenis, Piotr Kowalski, Adam Prahl, Tomasz Bączek
Nowadays, ionic liquids (ILs) are receiving more attention in various fields of analytical chemistry. Their contribution to the enhancement of the clean-up, extraction, separation and determination of trace amounts of various biologically important compounds in distinct matrices is well documented. Moreover, their importance as "green chemistry" solvents has been pointed out. Advanced analytical methods based on the IL-assisted microextraction and electrophoretic determination of minute concentrations of neurotransmitters (NTs) in samples are presented here for the first time...
August 15, 2018: Talanta
Moussa Yabré, Ludivine Ferey, Issa Touridomon Somé, Karen Gaudin
The greening of analytical methods has gained increasing interest in the field of pharmaceutical analysis to reduce environmental impacts and improve the health safety of analysts. Reversed-phase high-performance liquid chromatography (RP-HPLC) is the most widely used analytical technique involved in pharmaceutical drug development and manufacturing, such as the quality control of bulk drugs and pharmaceutical formulations, as well as the analysis of drugs in biological samples. However, RP-HPLC methods commonly use large amounts of organic solvents and generate high quantities of waste to be disposed, leading to some issues in terms of ecological impact and operator safety...
May 2, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Danielle Cristina da Silva, Cláudio Celestino Oliveira
Method for extraction and determination of amoxicillin, caffeine, ciprofloxacin, norfloxacin, tetracycline, diclofenac, ibuprofen, nimesulide, levonorgestrel, and 17 α -ethynylestradiol exploiting micellar liquid chromatography with PDA detector and solid-phase extraction was proposed. The usage of toxic solvents was low; the chromatographic separation of the medicaments was performed using a C18 column and mobile phases A and B containing 15.0% (v/v) ethanol, 3.0% (m/v) sodium dodecyl sulfate (SDS), and 0...
2018: Journal of Analytical Methods in Chemistry
Mehdi Moini
In the past few years, there has been a significant effort by the forensic science community to develop new scientific techniques for the analysis of forensic evidence. Forensic chemists have been spearheaded to develop information-rich confirmatory technologies and techniques and apply them to a broad array of forensic challenges. The purpose of these confirmatory techniques is to provide alternatives to presumptive techniques that rely on data such as color changes, pattern matching, or retention time alone, which are prone to more false positives...
May 2018: Electrophoresis
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