Development of novel molecularly imprinted solid-phase microextraction fibers and their application for the determination of antibiotic drugs in biological samples by SPME-LC/MSn

Novel molecularly imprinted polymer (MIP)-coated fibers for solid-phase microextraction (SPME) fibers were prepared by using linezolid as the template molecule. The characteristics and application of these fibers were investigated. The polypyrrole, polythiophene, and poly(3-methylthiophene) coatings were prepared in the electrochemical polymerization way. The molecularly imprinted SPME coatings display a high selectivity toward linezolid. Molecularly imprinted coatings showed a stable and reproducible response without any influence of interferents commonly existing in biological samples. High-performance liquid chromatography with spectroscopic UV and mass spectrometry (MS) detectors were used for the determination of selected antibiotic drugs (linezolid, daptomycin, amoxicillin). The isolation and preconcentration of selected antibiotic drugs from new types of biological samples (acellular and protein-free simulated body fluid) and human plasma samples were performed. The SPME MIP-coated fibers are suitable for the selective extraction of antibiotic drugs in biological samples

Poly(3-alkylthiophenes): new sorption materials for solid phase microextraction of drugs isolated from human plasma

A novel sorbent in solid phase microextraction (SPME) method based on poly(3-alkylthiophenes) was used in the isolation of linezolid from human plasma samples following liquid chromatography determination. The effect of extraction time on the sorption capacity of the SPME process was studied and pointed at 10 min both for adsorption and desorption. Poly(3-methylthiophene) and poly(3-nonylthiophene) were applied for the extraction of linezolid from water solutions. In plasma samples, four coatings including polythiophene and poly(3-penthylthiophene) were investigated. With these measurements, correlation coefficients were calculated in the range from 0.9820 to 0.9995, and the relative standard deviations were below 15%. That allowed claiming that the synthesized and described materials can be successfully applied in the analysis of linezolid also from other matrices such as urine or blood

Supramolecular recognition of estrogens via molecularly imprinted polymers

The isolation and preconcentration of estrogens from new types of biological samples (acellular and protein-free simulated body fluid) by molecularly imprinted solid-phase extraction has been described. In this technique, supramolecular receptors, namely molecularly imprinted polymers (MIPs) are used as a sorbent material. The recognition sites of MIPs were prepared by non-covalent multiple interactions and formed with the target 17β-estradiol as a template molecule. High-performance liquid chromatography with spectroscopic UV, selective, and a sensitive electrochemical CoulArray detector was used for the determination of 17β-estradiol, estrone, and estriol in simulated body fluid which mimicked human plasma

Clinical application of a rapid microbiological test based on capillary zone electrophoresis to assess local skin infection

<p>Abstract</p> <p>Background</p> <p>The basic clinical problem associated with infection treatment is the fact that classic, commonly and routinely used isolation and identification methods are based on long-term processes of a phenotypic analysis of microorganisms. Consequently sometimes, especially in small centres, rapid implementation of antibacterial treatment becomes delayed.</p> <p>The work presents the initial results of rapid microbiological identification based on an original method of capillary zone electrophoresis (CZE). The study involved the analysis of 78 biological samples from post-operative wounds and trophic ulcers.</p> <p>Results</p> <p>The attempt was made to identify individual bacterial species based on characteristic features of electropherograms achieved. Finally, G(+) cocci type bacteria and different G(-) rods were identified with sensitivity of 88.1% and specificity of 100%.</p> <p>Conclusions</p> <p>Based on the clinical trials using an electrophoretic technique in the field of microbiological diagnostics of infected exudate from a post-operative wound it can be concluded that it is a rapid and relatively sensitive method for initial identification of infectious pathogens.</p

Study of the Interactions of Ionic Liquids in IC by QSRR

The nature of ionic liquids (ILs) facilitates their analysis by ion chromatography which, unlike conventional high-performance liquid chromatography, enables analysis both of cations and anions. This paper describes a pioneering ion-chromatographic investigation of IL cations and statistical evaluation of quantitative structure–retention relationships with the objective of predicting the molecular mechanism responsible for retention. Eleven ionic liquid imidazolium and pyridinium cations were analyzed on a CS15 cation-exchange column by isocratic elution with acetonitrile–methanesulfonic acid mixtures. Structural descriptors of the cations obtained from molecular modeling were used to describe their hydrophobicity as determined by chromatography. The most statistically significant were three-term QSRR regression equations relating log kw to analyte n-octanol–water partition coefficient (log P), dipole moment (μ), solvent accessible surface area (ASAS), and hydration energy (HE). They indicate the important role of both hydrophobic and polar the retention of ILs on the CS15 column

Hydrophilic interaction liquid chromatography (HILIC)—a powerful separation technique

Hydrophilic interaction liquid chromatography (HILIC) provides an alternative approach to effectively separate small polar compounds on polar stationary phases. The purpose of this work was to review the options for the characterization of HILIC stationary phases and their applications for separations of polar compounds in complex matrices. The characteristics of the hydrophilic stationary phase may affect and in some cases limit the choices of mobile phase composition, ion strength or buffer pH value available, since mechanisms other than hydrophilic partitioning could potentially occur. Enhancing our understanding of retention behavior in HILIC increases the scope of possible applications of liquid chromatography. One interesting option may also be to use HILIC in orthogonal and/or two-dimensional separations. Bioapplications of HILIC systems are also presented

Determination of zearalenone and its metabolites in endometrial cancer by coupled separation techniques

This study presents a selective method of isolation of zearalenone (ZON) and its metabolite, α-zearalenol (α-ZOL), in neoplastically changed human tissue by accelerated solvent and ultrasonic extractions using a mixture of acetonitrile/water (84/16% v/v) as the extraction solvent. Extraction effectiveness was determined through the selection of parameters (composition of the solvent mixture, temperature, pressure, number of cycles) with tissue contamination at the level of nanograms per gram. The produced acetonitrile/water extracts were purified, and analytes were enriched in columns packed with homemade molecularly imprinted polymers. Purified extracts were determined by liquid chromatography (LC) coupled with different detection systems (diode array detection - DAD and mass spectrometry - MS) involving the Ascentis RP-Amide as a stationary phase and gradient elution. The combination of UE-MISPE-LC (ultrasonic extraction - molecularly imprinted solid-phase extraction - liquid chromatography) produced high (R ≈ 95–98%) and repeatable (RSD < 3%) recovery values for ZON and α-ZOL

Polymeric Functionalized Stationary Phase for Separation of Ionic Compounds by IC

Synthesis and properties are described of multilayered stationary phases containing quaternary amine functional groups used for the analysis of inorganic anions by ion chromatography. The bonded phases were characterized by elemental analysis, solid state 13C NMR spectroscopy and chromatographic methods. The surface of polyhydroxyethyl methacrylate (solid support) was coated with polymeric layers formed by condensation polymerization of primary amine with diepoxide. Each layer of the anion exchange stationary phase consisted of methylamine and 1,4-butanedioldiglycidyl ether copolymer. A series of stationary phases with different number of polymerized layers were tested. Separation of inorganic anions, such as F−, Cl−, NO2−, Br−, NO3−, were performed. Aqueous hydroxide, carbonate and bicarbonate solutions were used as mobile phases