Jacek Nowaczyk

Fibers with polypyrrole and polythiophene phases for isolation and determination of adrenolytic drugs from human plasma by SPME-HPLC

In this study, polypyrrole (PPy) and polythiophene (PTh) SPME coatings and their ability to extract selected adrenolytic drugs with different physico-chemical properties from standard solutions and human plasma samples were evaluated. In measurements metoprolol, oxprenolol, mexiletine, propranolol, and propaphenon were investigated. The main parameters such as extraction time, desorption conditions and pH influence were examined. Inter-day precisions were in range 0.1-2.0%, 1.1-2.9%, 1.3-2.6%, 0.1-2.6% and 0.3-2.1% for metoprolol, oxprenolol, mexiletine, propranolol and propaphenon, respectively. Accuracies were less than 15%, which was evaluated by analyzing preparation samples of five replicates. The method was successfully applied to human plasma samples spiked with selected adrenolytic drugs. The method was linear in the concentration range from 1 to 10microg/ml for all of studied adrenolytic drugs using human plasma samples. The PTh-SPME coating displayed higher extraction efficiency towards the target analytes in comparison to PPy-SPME. The reproducibility of the extraction using polypyrrole and polythiophene fibers was confirmed by variation coefficients lower than 8% and 3%, respectively.

Propionic and acetic acid pertraction through a multimembrane hybrid system containing TOPO or TBP

Abstract Liquid membrane transport (pertraction) of propionic (PA) and/or acetic (AA) acid has been studied in a multimembrane hybrid system (MHS): feed‖AEM|BLM|AEM‖stripping solution. The MHS was made up of strongly basic anion-exchange membrane (AEM) and a bulk liquid membrane (BLM) composed of hexane and tri-n-octylphosphinic oxide (TOPO) or tri-n-butylphosphate (TBP). Transport rates, and carrier-dependent facilitation factors (F) were determined as dependent on the feed and carrier concentration. It was found that TBP facilitates the pertraction of AA (F≈8) and does not influence the pertraction of PA, which predominantly permeates the BLM according to the solution-diffusion mechanism. In the case of TOPO, the negative effect of transport freezing characterized by F JPAhexane>JPATBP>JAATOPO>JAAhexane>JPATOPO. The facilitation factors change typically in the sequence: (AA-TBP, F>1)>(AA-TOPO, F>1)>(PA-TBP, F≤1)>(PA-TOPO, F

A new way of solid-phase microextraction fibers preparation for selected antibiotic drug determination by HPLC–MS

The polypyrrole (PPy) and polythiophene (PTh) solid phase microextraction (SPME) coatings were obtained with the use of the electropolymerisation and linear sweep voltammetry. Such fibers were modified by an ozone treatment in a gaseous phase in the concentration of 2.1 ± 0.2 × 10(-5) mol dm(-3). Both kinds of fibers were applied in the microextraction of linezolid from standard solutions to compare the extraction efficiencies displayed by these sorption phases. In these investigations a better adsorption capacity was obtained for polypyrrole fibers and hence only these kinds of fibers were utilized in the measurements from human plasma. In all measurements the concentrations of the drugs were in the range from 1 to 20 μg ml(-1) (standard solutions) and 1 to 15 μg ml(-1) (human plasma). Before the measurements, an optimization of the desorption solution experiments was performed. The correlation coefficients (R) obtained in the standard solution and human plasma were in the range from 0.8399 to 0.9970. The relative standard deviations (RSDs) were in the range of 0.1-7.6%.

Separation of propionic and acetic acid by pertraction in a multimembrane hybrid system

Abstract Studies have been made on transport rates and separation of propionic over acetic acid by the solution-diffusion type pertraction in a multimembrane hybrid system (MHS). The membrane system has been composed of two hydrophilic, strongly basic or acidic, polymer membranes separated by a hydrophobic bulk liquid membrane. Separation of propionic and acetic acids from their aqueous solutions (0.1–0.8 M) or real fermentation broth has been studied. Experimentally observed mass transfer coefficients ( k ) range from 3.5×10 −6 to 1.5×10 −5 cm/s with the higher values for propionic acid. In the case of fermented broth the fluxes were found to depend on its pH and the pretreatment of the feed. The selectivity SEL AA PA evaluated as the ratio of propionic and acetic acid fluxes can attain values ranging from 3.5 to 5.5. The overall transport mechanism is consistent with a solution-diffusion mechanism typical for liquid membranes operating without a carrier. The fluxes and selectivity of the membrane system in respect to acetic and propionic acid have been found to depend on the viscosity of liquid membrane phase and solubility parameters characterizing both acids and solvents. A model based on fundamental physicochemical properties of the permeants and solvents (diffusion coefficients, solubility parameters and molar volumes) has been elaborated, and experimentally verified.

Membrane transport of organics. II. Permeation of some carboxylic acids through strongly basic polymer membrane

The permeability characteristics of the strongly basic polymer membrane Neosepta® AFN-7, (Tokuyama Soda) have been studied for acetic, propionic, lactic, tartaric, oxalic, and citric acid. The results were interpreted by using the model of transport in reactive membranes. The specific constants, that is, the maximum flux J max , the reactivity constant K, and the permeability coefficient (P), were calculated using the experimental quasi-stationary fluxes and the equation derived as a sum of reaction-diffusion (Michaelis-Menten-type), and the solution-diffusion transport equation. The constants K and J max were found to range from 0.1 to 5 dm 3 mol 1 and from 0.4 × 10 7 to 2.5 × 10 -7 mol cm -2 s 1 depending, on the acid properties. The values of K and J max were correlated with the dissociation constants K dis.acid , and the diffusion coefficients D aq.acid in aqueous media, respectively. It was found that the reaction- diffusion flux is predominating for all acids, except for the lactic one, when the feed concentration is lower than 0.5 mol dm -3 .

Preparation and characterization of microporous fibers for sample preparation and LC‐MS determination of drugs

The aim of this study was the preparation of polypyrrole (PPy) fibers for solid phase microextraction (SPME). PPy coatings were obtained during the electrochemical polymerization process. The utility of various metal wires (Fe, Cu, Ag, Cu/Ag, kanthal and medical stainless steel) as a support for polymers was compared. Various experimental conditions of the synthesis process such as scan rate, voltage limits and number of scans and deposition time were applied. The average polymer thickness was in the range of 7-125 microm and its weight was in the scope of 0.65-5.6 mg. Different techniques, mainly elemental analysis, Fourier transform infrared spectroscopy, microscopy, and chromatography were performed for the characterization of obtained fibers with microporous structure. The extraction efficiency of cardiovascular drugs (metoprolol, propranolol, oxprenolol, propafenone and mexiletine) by means of fibers was tested. The concentration of mentioned compounds in standard solution was in the span of 10-150 ng/mL. LC-MS was employed for determination of drugs in desorption solution. LODs varied from 0.013 to 1.51 ng/mL for metoprolol and mexiletine respectively. The repeatability of extraction was obtained with the RSD values lower than 10%.

Ozonization of electronic conducting polymersI. Copolymers based on poly[3-nonylthiophene]

Abstract The ozonization of a group of new conducting copolymers based on 3-nonylthiophene and 2-substituted-3-ethylthiophene was investigated. The reaction products have been studied using solid state 13 C NMR, and FTIR spectroscopy. Polymers ozonized were laboratory made copolymers: poly[3-(2-(9-anthrylcarboxy)ethyl)thiophene-co-3-nonylthiophene] ( P[AET-co-3NT] ), poly[3-(2-acetoxyethyl)thiophene-co-3-nonylthiophene] ( P[AcET-co-3NT] ), poly[3-(2-hydroxyethyl)thiophene-co-3-nonylthiophene] ( P[HET-co-3NT] ). Chemical and electrical stability of the polymers in ozonized air, was investigated. These properties are important due to potential application of such polymers as a electroactive components in manufacturing of light emitting diode devices (LEDs). Ozone present in the troposphere is one of the strongest oxidizing agents acting on polymeric materials, especially those having unsaturated bonds. The results of this research indicate that there are no significant changes in chemical structure of P[AcET-co-3NT] after ozone treatment. But in the case of P[AET-co-3NT] and P[HET-co-3NT] significant changes in conjugated bonds system were observed. In consequence electrical properties of polymers changed. Additionally it was found that ozonization causes distinct deterioration of optical properties.

EMULSION POLYMERIZATION OF THIOPHENE – THE NEW WAY OF CONDUCTING POLYMERS SYNTHESIS

The aim of this study was to investigate the new method of polythiophene polymerization. It was made an attempt of the chemical oxidation of thiophene in aqueous medium without the addition of any surfactant. The oxidative compound applied in the synthesis was gaseous ozone. Resulting polymer was obtained in the form of nanospheres dispersed in water. The method developed in this study allow to obtain the polythiophene nanoparticles. Further study is required to fully identify the resulting product properties in comparison with polymer obtained in other methods.