The effect of biosilver nanoparticles on different bacterial strains' metabolism reflected in their VOCs profiles.

The use of silver nanoparticles has become in recent years a growing interest for many researchers, due to their bacteriostatic and bactericidal properties and synergetic effects when they are used together with antibiotics, for an increased efficiency and less adverse reactions in the treatment of bacterial infections. Gas chromatography coupled with mass spectrometry (GC-MS), which is considered 'the golden standard' in chemical analysis, has proven to be a reliable instrument, perfectly suitable for clinical analysis. In this work, three bacterial strains, Escherichia coli (E. coli), Klebsiella oxytoca (K. oxytoca) and Staphylococcus saccharolyticus (S. saccharolyticus) were treated with biosilver nanoparticles (bioAgNPs). Headspace and GC-MS analysis was used for the detection of volatile metabolites. We observed decreased amounts of alcohols and carbonyl components (mainly ketones) in K. oxytoca and S. saccharolyticus bacteria incubated with silver. In contrast, biosilver nanoparticles added to E. coli increased the amount of VOCs, mainly hydrocarbons and alcohols. Our results have successfully demonstrated that the treatment of bacterial strains with bioAgNPs has a direct influence on their VOC profiles, by modifying the number of metabolic markers. Connected with this, the inhibition of bacteria is supposed, and consequently both the bacteriostatic and/or bactericidal effects of bioAgNPs on all three bacterial strains investigated were revealed.

The analysis of healthy volunteers' exhaled breath by the use of solid-phase microextraction and GC-MS.

We analysed breath and inhaled room air samples from 39 healthy volunteers (28 non-smokers, 8 smokers and 3 ex-smokers) by SPME-GC-MS. Mixed expiratory and indoor air samples were collected in freshly cleaned Tedlar bags. Eighteen millilitres of each sample were transferred into sealed, evacuated glass vials, preconcentrated by solid-phase microextraction (SPME, carboxen/polydimethylsiloxane) and investigated by gas chromatography with mass spectrometric detection (GC-MS). For the unequivocal identification of potential marker compounds, pure calibration mixtures of reference compounds (depending on commercial availability) were prepared to determine the retention time and mass spectra with respect to our analytical setting. Applying the adapted SPME-GC/MS method with limit of detection in the high ppb range (0.05-15.00 ppb), we succeeded in identifying altogether 38 compounds with concentrations in exhaled breath being at least 50% higher than concentration in inhaled air. From these 38 compounds, 31 were identified not only by the spectral library match but also by retention time of standards. A comparison of retention times and spectrum obtained for standards and determined compounds was performed. We found hydrocarbons (isoprene, 2-pentene, 2-methyl-1-pentene, benzene, toluene, p-cymene, limonene, 2,4-dimethylheptane, n-butane), ketones (acetone, hydroxypropanone, methylvinyl ketone), ethers (dimethyl ether, 1,3-dioxolane), esters (ethyl acetate), aldehydes (propanal, hexanal, heptanal, acrolein) and alcohols (ethanol, 2-metoxyethanol, isopropyl alcohol, 2,2,3,3- tetramethylcyclopropanemethanol, 3,4-dimethylcyclohexanol). Proper identification of compounds in different cohorts of patients and volunteers is the base for further investigation of origin, biochemical background and distribution of potential breath biomarkers.

Organic and inorganic pollution of the Vistula River basin.

The main aim of this work is focused therefore on water quality assessment of the Vistula river and its primary tributaries. The study presents the analytical results of the contamination level of different organic and inorganic pollutants as well as the chemometric evaluation of the entire data set. A broad spectrum of compounds have been determined, including pesticides, polichlorinated biphenyls (PCBs), phenols, polycyclic aromatic hydrocarbons (PAHs), heavy metals, inorganic ions and some aggregate parameters like BOD. Majority of the organic xenobiotics have been analyzed for first time in the Vistula region on a large, long-term scale. Chemometric evaluation allowed the determination of natural clusters and groups of monitoring locations with similar pollution character. Chemometric analysis confirmed the classification of water purity of the Vistula River basin is related to the land utilization character in this region.

Preliminary study of volatile organic compounds from breath and stomach tissue by means of solid phase microextraction and gas chromatography-mass spectrometry.

The determination of volatile organic compounds (VOCs) in exhaled air and stomach tissue emission for the detection of cancer has been investigated. Solid phase microextraction (SPME) was used for sample preconcentration. The method presented in this paper showed satisfactory precision (RSD below 11%), linearity in the range of 2.8-136 ppb and limit of detection ranging from 0.6 to 2.1 ppb. The breath and emission from cancer tissue were collected from three patients with stomach cancer. Acetone, carbon disulfide, 2-propanol, ethyl alcohol and ethyl acetate were identified in breath and tissue samples. These compounds have been assumed as endogenous. Acetone ratio (AR) was calculated for carbon disulfide, 2-propanol and n-butane. The AR for carbon disulfide was found to be higher for normal tissue (20.64-44.95) than for emission from cancer tissue (2.01-18.20). A limitation of this study is that only a few clinical samples were investigated. These results should be evaluated as preliminary because of the small number of patients examined.

Isolation and determination of ginsenosides in American ginseng leaves and root extracts by LC-MS.

Ginseng saponins (ginsenosides) were extracted from the root and leaves of locally cultivated American ginseng (Panax quinquefolium L.). For the isolation of compounds from plant samples three different extraction methods were utilized: accelerated solvent extraction, the ultrasound-assisted solvent extraction and mechanical shaking assisted solvent extraction. The separation of compounds was achieved with a water-acetonitrile gradient system using a C18 reversed-phase column. Target compounds were identified in MS(2) and MS(3) experiments. The relative distribution of these ginsenosides in each root and leaf extract was established. The limit of detection of the method was less than 30 ng/ml. Recovery of ginseng saponins in spiked samples exceeded 80%, while the relative standard deviation ranged from 7.1 to 9.1%. The total concentrations of ginsenosides were 41 and 13 mg/g in root and leaves.

Determination of phenolic derivatives of antipyrine in plasma with solid-phase extraction and high-performance liquid chromatography-atmospheric-pressure chemical ionization mass spectrometry.

This manuscript describes a method to determine antipyrine and its phenolic derivatives in plasma by reversed-phase high-performance liquid chromatography-mass spectrometry (RP-HPLC-MS). The sample pretreatment consisted of a C18 solid-phase extraction (SPE), to remove the salts and proteins. The retention behavior of antipyrine and its phenolic derivatives in the SPE procedure was estimated by the k values determined on a C18 HPLC column at different pH values and with different buffer compositions. Recoveries of antipyrine and its phenolic products were 90% in water and 100% in plasma. Atmospheric pressure chemical ionization (APCI) was used to introduce the components into the mass spectrometer. The mass spectrometer was operated in the single ion monitoring mode (SIM mode) as well as in the selective reaction (SR) mode. The SR mode or tandem MS resulted in the best signal-to-noise ratio, with a detection limit for antipyrine of 6 pg in 20 microl. For the different phenolic antipyrines, different target ions were used and conditions were optimized for each.