Pawel Olszowy

Polypyrrole solid phase microextraction: A new approach to rapid sample preparation for the monitoring of antibiotic drugs.

Simple or even rapid bioanalytical methods are rare, since they generally involve complicated, time-consuming sample preparation from the biological matrices like LLE or SPE. SPME provides a promising approach to overcome these limitations. The full potential of this innovative technique for medical diagnostics, pharmacotherapy or biochemistry has not been tapped yet. In-house manufactured SPME probes with polypyrrole (PPy) coating were evaluated using three antibiotics of high clinical relevance - linezolid, daptomycin, and moxifloxacin - from PBS, plasma, and whole blood. The PPy coating was characterised by scanning electron microscopy. Influences of pH, inorganic salt, and blood anticoagulants were studied for optimum performance. Extraction yields were determined from stagnant media as well as re-circulating human blood using the heart-and-lung machine model system. The PPy-SPME fibres showed high extraction yields, particularly regarding linezolid. The reproducibility of the method was optimised to achieve RSDs of 9% or 17% and 7% for SPME from stagnant or re-circulating blood using fresh and re-used fibres, respectively. The PPy-SPME approach was demonstrated to meet the requirements of therapeutic monitoring of the drugs tested, even from re-circulating blood at physiological flow rates. SPME represents a rapid and simple dual-step procedure with potency to significantly reduce the effort and expenditure of complicated sample preparations in biomedical analysis.

New coated SPME fibers for extraction and fast HPLC determination of selected drugs in human blood.

Polythiophene (PTh) and polypyrrole (PPy) as sorbent phases for solid phase microextraction (SPME) were applied in order to extract the multi-resistant Staphylococcus aureus (MRSA) antibiotic drugs (linezolid and daptomycin) from whole blood followed by high performance liquid chromatography (HPLC) determination with UV detection. Relative standard deviations (RSDs) of in vitro and pseudo in vivo measurements performed in whole blood were in the range of 4.58-15.91% and 6.09-17.33% for linezolid and daptomycin, respectively. Determination coefficients (R(2)) were in range of 0.9884-0.9945 and 0.9807-0.9818 for linezolid and daptomycin, respectively. This study proved better adsorption capacity of PTh SPME coating compared to PPy coating for both, linezolid and daptomycin.

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.

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%.

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%.

Urine sample preparation for proteomic analysis.

Sample preparation for both environmental and more importantly biological matrices is a bottleneck of all kinds of analytical processes. In the case of proteomic analysis this element is even more important due to the amount of cross-reactions that should be taken into consideration. The incorporation of new post-translational modifications, protein hydrolysis, or even its degradation is possible as side effects of proteins sample processing. If protocols are evaluated appropriately, then identification of such proteins does not bring difficulties. However, if structural changes are provided without sufficient attention then protein sequence coverage will be reduced or even identification of such proteins could be impossible. This review summarizes obstacles and achievements in protein sample preparation of urine for proteome analysis using different tools for mass spectrometry analysis. The main aim is to present comprehensively the idea of urine application as a valuable matrix. This article is dedicated to sample preparation and application of urine mainly in novel cancer biomarkers discovery.

Nanoporous Conducting Polymer-Based Coatings in Microextraction Techniques for Environmental and Biomedical Applications.

ABSTRACT Biologically active compounds constitute a wide group of chemicals, therefore it is a big challenge to create sorbents that are sensitive as well as selective. Development of nanoporous sorbents based on conducting polymers has expanded the boundaries of detection and quantification. Additionally, electrochemical synthesis used to deposit polymeric coatings directly on solid supports makes it possible to control physico-chemical properties of such sorbents. Besides the development of new polymeric nanoporous materials, the question of selectivity needs to be addressed. One possibility, successfully adapted to solid-phase microextraction, is molecular imprinting. Coatings created with this technology allow obtaining higher selectivity, with sensitivity at a constantly high level. The main aim of this review is to present comprehensively the concept of nanoporous sorbents based on conducting polymers, possible coating methods with their characteristics, and their various applications. This article focuses on applications in environmental and biomedical analyses.