The advantages of using mixtures of organic solvents for the separation of labeled oligosaccharides on the amide stationary phase under hydrophilic interaction liquid chromatography conditions are presented. The effect of the type of buffer as well as solvent or their mixtures on retention of uracil, saccharide labeling reagents (2-aminobenzoic acid, 2-aminobenzamide, ethyl 4-aminobenzoate, procainamide), and corresponding labeled saccharides were evaluated. The successful isocratic separation of labeled isomeric trisaccharides (maltotriose, panose, and isomaltotriose) was achieved in the mobile phase consisting of a 90% (v/v) mixture of organic solvents (methanol/acetonitrile 60:40) and 10% (v/v) 30 mM ammonium formate, pH 3.3. Changing the volume ratio between methanol/acetonitrile from 60:40 to 50:50 (v/v) allowed to obtain the separation of di-, tri-, and tetrasaccharides labeled by ethyl 4-aminobenzoate in less than 10.5 min.
- Klíčová slova
- HILIC, Mass spectrometry, Oligosaccharide, Saccharide/glycan labeling, Selectivity,
- MeSH
- acetonitrily chemie MeSH
- amidy chemie MeSH
- chemické techniky analytické přístrojové vybavení metody MeSH
- chromatografie kapalinová * MeSH
- formiáty chemie MeSH
- hydrofobní a hydrofilní interakce MeSH
- isomerie MeSH
- oligosacharidy izolace a purifikace MeSH
- ortoaminobenzoáty chemie MeSH
- rozpouštědla chemie MeSH
- sacharidy chemie MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- acetonitrile MeSH Prohlížeč
- acetonitrily MeSH
- amidy MeSH
- anthranilamide MeSH Prohlížeč
- anthranilic acid MeSH Prohlížeč
- formiáty MeSH
- formic acid MeSH Prohlížeč
- oligosacharidy MeSH
- ortoaminobenzoáty MeSH
- rozpouštědla MeSH
- sacharidy MeSH
About eight years ago, a new automation approach and flow technique called "Lab-In-Syringe" was proposed. It was derived from previous flow techniques, all based on handling reagent and sample solutions in a flow manifold. To date Lab-In-Syringe has evidently gained the interest of researchers in many countries, with new modifications, operation modes, and technical improvements still popping up. It has proven to be a versatile tool for the automation of sample preparation, particularly, liquid-phase microextraction approaches. This article aims to assist newcomers to this technique in system planning and setup by overviewing the different options for configurations, limitations, and feasible operations. This includes syringe orientation, in-syringe stirring modes, in-syringe detection, additional inlets, and addable features. The authors give also a chronological overview of technical milestones and a critical explanation on the potentials and shortcomings of this technique, calculations of characteristics, and tips and tricks on method development. Moreover, a comprehensive overview of the different operation modes of Lab-In-Syringe automated sample pretreatment is given focusing on the technical aspects and challenges of the related operations. We further deal with possibilities on how to fabricate required or useful system components, in particular by 3D printing technology, with over 20 different elements exemplarily shown. Finally, a short discussion on shortcomings and required improvements is given.
- Klíčová slova
- 3D printing of instrument elements, Lab-In-Syringe, automation of sample pretreatment, potentials and troubles, system setup and operation modes, tips and tricks in method development,
- MeSH
- chemické techniky analytické přístrojové vybavení metody normy MeSH
- injekční stříkačky * MeSH
- laboratorní automatizace * MeSH
- limita detekce MeSH
- reprodukovatelnost výsledků MeSH
- Publikační typ
- časopisecké články MeSH
The aim of this article is to study the modification of an inner capillary wall with sol-gel coating (pure silica sol-gel or silica sol-gel containing porphyrin-brucine conjugate) and determine its influence on the separation process using capillary electrophoresis/electrochromatography method. After modification of the inner capillary surface the separation of analytes was performed using two different phosphate buffers (pH 2.5 and 9.0) and finally the changes in electrophoretic mobilities of various samples were calculated. To confirm that the modification of the inner capillary surface was successful, the parts of the inner surfaces of capillaries were observed using scanning electron microscopy. The analytes used as testing samples were oligopeptides, nucleosides, nucleobases and finally nucleotides.
- Klíčová slova
- Capillary electrochromatography (CEC), Nucleo-compounds, Oligopeptides, Open-tubular capillary electrochromatography (OT-CEC), Porphyrin, Scanning electron microscopy (SEM), Sol–gel methods,
- MeSH
- chemické techniky analytické přístrojové vybavení metody MeSH
- kapilární elektrochromatografie * MeSH
- mikroskopie elektronová rastrovací MeSH
- nukleosidy izolace a purifikace MeSH
- nukleotidy izolace a purifikace MeSH
- oligopeptidy izolace a purifikace MeSH
- změna skupenství MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- nukleosidy MeSH
- nukleotidy MeSH
- oligopeptidy MeSH
This review summarizes the development and the applications of capillary electrochromatographic techniques pertinent to the analysis of proteins and peptides, which took place over the last 10 years (2006-mid-2016). This "hybrid" technique is useful for the analysis of a broad spectrum of proteins and peptides and is an approach that is complementary to the liquid chromatographic and the capillary electrophoretic analysis. All modes of capillary electrochromatography are described here, which includes particle-packed columns, monolithic stationary phases, and open-tubular capillary electrochromatography.
- Klíčová slova
- Capillary electrochromatography, Peptides, Proteins,
- MeSH
- chemické techniky analytické přístrojové vybavení MeSH
- chromatografie kapalinová MeSH
- kapilární elektrochromatografie * MeSH
- peptidy analýza MeSH
- proteiny analýza MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
- Názvy látek
- peptidy MeSH
- proteiny MeSH
This review summarizes principles and current stage of development of fiber-optic chemical sensors (FOCS) and biosensors (FOBS). Fiber optic sensor (FOS) systems use the ability of optical fibers (OF) to guide the light in the spectral range from ultraviolet (UV) (180 nm) up to middle infrared (IR) (10 μm) and modulation of guided light by the parameters of the surrounding environment of the OF core. The introduction of OF in the sensor systems has brought advantages such as measurement in flammable and explosive environments, immunity to electrical noises, miniaturization, geometrical flexibility, measurement of small sample volumes, remote sensing in inaccessible sites or harsh environments and multi-sensing. The review comprises briefly the theory of OF elaborated for sensors, techniques of fabrications and analytical results reached with fiber-optic chemical and biological sensors.
- Klíčová slova
- chemical sensor, enzymatic sensor, fiber-optic sensor, immobilization of biologicals, tapered optical fiber, whole cell biosensor,
- MeSH
- biosenzitivní techniky přístrojové vybavení MeSH
- biotest přístrojové vybavení MeSH
- chemické techniky analytické přístrojové vybavení MeSH
- design vybavení MeSH
- lidé MeSH
- optická vlákna * MeSH
- technologie optických vláken přístrojové vybavení MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
A macroporous particulate support prepared previously by reactive gelation under shear and functionalized with poly(N-isopropylacrylamide), PNIPAM, brushes of variable length is applied for temperature-responsive chromatography, whereby temperature modulates hydrophobic interactions. Several different analytes, including small pharmaceuticals, peptides, proteins and monoclonal antibodies are employed. Contrary to the most commonly observed behavior in conventional chromatography, increasing retention is observed at elevated temperatures. Peak broadening is quantified using the peak standard deviation, which depends on both the polymer chain conformation and analyte adsorptivity. The favorable effect of grafted polymer thickness on retention becomes progressively less pronounced for thicker grafted PNIPAM layers. The effect of eluent composition on solute-sorbent interactions was investigated by introducing NaCl, methanol, dioxane and by varying the pH. Salt or organic solvent addition affects apart from the analytes solution properties, the hydrophobicity of the stationary phase itself. Frontal analyses performed at different temperatures to determine dynamic binding capacities, indicate small mass transfer resistances imposed by this novel packing material.
- Klíčová slova
- ATRP, Analyte retention factor, Conformational transition, Frontal analysis, Grafted brushes, Hydrophobic interactions, LCST, Macroporous particles, Monoclonal antibodies, Perfusion, Poly(N-isopropylacrylamide), Reactive gelation, Standard deviation, Steroids, Temperature-responsive chromatography,
- MeSH
- chemické techniky analytické přístrojové vybavení metody MeSH
- chromatografie * MeSH
- hydrofobní a hydrofilní interakce MeSH
- léčivé přípravky chemie MeSH
- roztoky chemie MeSH
- teplota * MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- léčivé přípravky MeSH
- roztoky MeSH
Zwitterionic methacrylate based polymeric monolithic columns were prepared in two-step polymerizations, with reduced polymerization times. Characteristic properties such as hydrodynamic permeability, porosity, retention factors, and pore size distribution charts were used for column evaluation. A scaffold column was fabricated by polymerization of poly(lauryl methacrylate-co-tetraethyleneglycol dimethacrylate) and was used without further modification as a support for a poly(N,N-dimethyl-N-methacryloxyethyl-N-(3-sulfopropyl)ammonium betaine-co-bisphenol A glycerolate dimethacrylate) second monolith layer with zwitterionic functionality, for HILIC separations. An additional internal structure was formed by the second monolithic layer. The fabrication procedure was reproducible with RSD<5%. Field emission scanning electron microscopy has also been used to investigate column pore morphology, using a novel technique where the polymeric material is imaged directly, without coverage with a conducting film or particles. The new polar monolithic columns were used for HILIC separations of phenolic acids, flavones, nucleosides, and bases of nucleic acids, with similar efficiencies but different selectivities for zwitterionic methacrylate monolithic columns recently prepared by single step polymerization.
- Klíčová slova
- HILIC, ISEC, Incomplete polymerization, Polymer monolith,
- MeSH
- chemické techniky analytické přístrojové vybavení MeSH
- chromatografie kapalinová přístrojové vybavení MeSH
- hydrofobní a hydrofilní interakce MeSH
- kyseliny polymethakrylové chemie MeSH
- nukleosidy analýza MeSH
- permeabilita MeSH
- polymerizace MeSH
- polymery chemie MeSH
- poréznost MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- kyseliny polymethakrylové MeSH
- nukleosidy MeSH
- polymery MeSH
- polymethacrylic acid MeSH Prohlížeč
In this study a strategy to immobilize phospholipids onto a polymer-based stationary phase is described. Methacrylate-based monoliths in capillary format (150×0.1mm) were modified by soybean phosphatidylcholine through 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide coupling to obtain stationary phases suitable to mimic cell surface membranes. The covalent coupling reaction involves the phosphate group in phospholipids; therefore, the described methodology is suitable for all types of phospholipids. Immobilization of soy bean phosphatidylcholine on the monolith was confirmed by attenuated total reflectance Fourier transform infrared spectroscopy and gas chromatography-mass spectrometry of the fatty alcohol profile, generated upon reductive cleavage of the fatty acyl side chains of the phospholipid on the monolith surface with lithium aluminium hydride. The prepared stationary phases were evaluated through studies on the retention of low-molar mass model analytes including neutral, acidic, and basic compounds. Liquid chromatographic studies confirmed predominant hydrophobic interactions between the analytes and the synthesized stationary phase; however, electrostatic interactions contributed to the retention as well. The synthesized columns showed high stability even with fully aqueous mobile phases such as Dulbecco's phosphate-buffered saline solution.
- Klíčová slova
- ATR-FTIR, Analyte–membrane interaction, Capillary LC, Immobilized artificial membrane, Monolithic column, Phospholipids,
- MeSH
- biomimetika MeSH
- chemické techniky analytické přístrojové vybavení metody MeSH
- chromatografie kapalinová přístrojové vybavení MeSH
- ethyldimethylaminopropylkarbodiimid chemie MeSH
- fosfatidylcholiny chemie MeSH
- fosfolipidy chemie MeSH
- hydrofobní a hydrofilní interakce MeSH
- methakryláty chemie MeSH
- polymery chemie MeSH
- voda chemie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- ethyldimethylaminopropylkarbodiimid MeSH
- fosfatidylcholiny MeSH
- fosfolipidy MeSH
- methakryláty MeSH
- polymery MeSH
- voda MeSH
Synthetic cannabinoids have gained popularity due to their easy accessibility and psychoactive effects. Furthermore, they cannot be detected in urine by routine drug monitoring. The wide range of active ingredients in analyzed matrices hinders the development of a standard analytical method for their determination. Moreover, their possible side effects are not well known which increases the danger. This review is focused on the sample preparation and the determination of synthetic cannabinoids in different matrices (serum, urine, herbal blends, oral fluid, hair) published since 2004. The review includes separation and identification techniques, such as thin layer chromatography, gas and liquid chromatography and capillary electrophoresis, mostly coupled with mass spectrometry. The review also includes results by spectral methods like infrared spectroscopy, nuclear magnetic resonance or direct-injection mass spectrometry.
- Klíčová slova
- Biological matrices, Herbal blends, Mass spectrometry, New designer drugs, Separation methods, Synthetic cannabinoids,
- MeSH
- chemické techniky analytické přístrojové vybavení metody MeSH
- chromatografie kapalinová přístrojové vybavení metody MeSH
- chromatografie na tenké vrstvě přístrojové vybavení metody MeSH
- elektroforéza kapilární přístrojové vybavení metody MeSH
- extrakce na pevné fázi přístrojové vybavení metody MeSH
- hmotnostní spektrometrie přístrojové vybavení metody MeSH
- kanabinoidy analýza metabolismus farmakokinetika farmakologie MeSH
- lidé MeSH
- nové syntetické drogy analýza metabolismus farmakokinetika farmakologie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
- Názvy látek
- kanabinoidy MeSH
- nové syntetické drogy MeSH
Enhanced sensitivity for determination of basic drugs in body fluids was achieved by in-line coupling of extraction across supported liquid membrane (SLM) to large electrokinetic injection and transient isotachophoresis-capillary zone electrophoresis (tITP-CZE) in commercial CZE instrument. Twelve cm long tITP plug of 300mM ammonium acetate was formed in the separation capillary just before the electrokinetic injection of acceptor solution containing nortriptyline, haloperidol and loperamide extracted across the SLM. The tITP plug ensured efficient stacking and preconcentration of the injected basic drugs due to the tITP action of ammonium and the drugs were then separated by CZE using 5.2M acetic acid as background electrolyte. No interferences were observed from highly-abundant body fluid species (NaCl and human serum albumin) due to the excellent clean-up properties of SLMs and analytical sensitivity increased up to 340 times compared to SLM extractions coupled in-line to CZE with standard hydrodynamic injections. The SLM-tITP-CZE method was characterized by good repeatability (RSDs of peak areas below 7.8%), linearity over two orders of magnitude (r(2) better than 0.994) and limits of detection (defined as 3×S/N) between 3 and 45μg/L. Interfacing of SLM extractions to CZE instrumentation was achieved by low-cost, disposable micro-extraction devices, which can be routinely prepared in every analytical laboratory. These devices eliminated sample carry-over, minimized the need for manual sample handling and ensured fully automated determination (including extraction, injection, preconcentration and separation) of the three basic drugs in 20μL of untreated body fluids.
- Klíčová slova
- Capillary electrophoresis, Complex samples, In-line sample pretreatment, Supported liquid membranes, Transient isotachophoresis,
- MeSH
- chemické techniky analytické přístrojové vybavení metody MeSH
- elektroforéza kapilární * MeSH
- izotachoforéza * MeSH
- lidé MeSH
- membrány umělé MeSH
- tělesné tekutiny chemie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- membrány umělé MeSH
