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Wyniki wyszukiwania dla: SPE-LC-MS
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Rain Gardens LC_MS/MS analysis dataset
Dane BadawczeThis dataset contains the results of samples analysis (target analysis with certified reference materials) using ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS, Shimadzu, Japan).
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Unveiling the Pool of Metallophores in Native Environments and Correlation with Their Potential Producers
PublikacjaFor many organisms, metallophores are essential biogenic ligands that ensure metal scavenging and acquisition from their environment. Their identification is challenging in highly organic matter rich environments like peatlands due to low solubilization and metal scarcity and high matrix complexity. In contrast to common approaches based on sample modification by spiking of metal isotope tags, we have developed a two-dimensional...
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Presence of antibiotics in the aquatic environment in Europe and their analytical monitoring: Recent trends and perspectives
PublikacjaThe presence of antibiotics and their metabolites in the aquatic environment exerts a negative impact on all organisms. Moreover, the easy migration of these substances to drinking water may also have serious consequences for public health, such as drug resistance. Although antibiotics and their metabolites are detected in surface waters and wastewater, there are still no systemic solutions preventing environmental pollution with...
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Determination of sex hormone concentration in wastewater samples.
Dane BadawczeConcentration levels of five selected steroid hormones in influent and effluent waters from wastewater treatment plant were determined using SPE(C18)-HPLC-ESI/MS/MS method. Sex hormones like: estradiol, estriol, estrone, 17-α-ethynyloestradiol, progesterone were present in all influent wastwater samples.
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Assay of Cystathionine-γ-synthase (CaStr2p) activity determination.
Dane BadawczeThe study aimed to obtain conditions optimal for the activity of Candida albicans cystathionine-γ-synthase (CaStr2p) determination. The selection of appropriate reaction conditions included the identification of the reaction buffer and its pH, substrate, and enzyme concentrations. The activity of Str2p was measured by the detection of decrease of the...
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Activity assay of O-Acetyl-L-homoserine sulfhydrylase (CaMet15p).
Dane BadawczeThe study aimed to obtain conditions optimal for the activity of O-acetyl-L-homoserine sulfhydrylase (CaMet15p) and a method suitable for its measurement. The selection of appropriate reaction conditions included the identification of the reaction buffer and its pH, substrate and enzyme concentrations. The activity of CaMet15p was measured by the detection...
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Analytical data on molecular umbrella: cispentacin and molecular umbrella: fluorescent probe conjugates
Dane BadawczeAnalytical data (NMR, MS, FTIR) for nine conjugates of molecular umbrella with cispentacin, Lys(Mca) or Nap-NH2. The conjugates have been rationally designed as potential antifungal agents. 1H NMR and 13C NMR spectra were obtained at 500 MHz Varian Unity Plus spectrometer and the deuterated solvents were used as internal locks. High-resolution mass...
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Elucidation of transformation pathway of ketoprofen, ibuprofen, and furosemide in surface water and their occurrence in the aqueous environment using UHPLC-QTOF-MS
PublikacjaThe identification and determination of transformation products (TPs) of pharmaceuticals is essential nowadays, in order to track their fate in the aqueous environment and, thus, to estimate the actual pollution. However, this is a challenging task due to the necessity to apply high-resolution instruments enable to detect known and unknown compounds. This work presents the use of liquid chromatography quadrupole time-of-flight...
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Determination of isoprostanes in exhaled breath condensate samples by liquid chromatography coupled with tandem mass spectrometry
PublikacjaOxidative stress (OS) is a state of imbalance between continuously generating reactive oxygen species (ROS) during normal cell metabolism and mechanism of detoxifying oxygen radicals through a network of antioxidative enzymes. Isoprostanes are prostaglandin -like substances that are produced in vivo primarily by free radical-induced peroxidation of arachidonic acid. The measurement of isoprostanes in biological fluids and/or tissue...
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Glutathione conjugation of the antitumor-active 1-nitroacridine derivatives compounds C-857 and C-1748 – the major role of glutathione S-transferase M1-1
Dane BadawczeObjectives: C-857 and C-1748 are antitumor-active agents, monomers of unsymmetrical bisacridine derivatives. The aim of this study was to analyze their glutathione (GSH) conjugation in vitro in the presence of glutathione S-transferase (GST) M1-1.
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Metody chromatograficzne
Kursy OnlineCelem nadrzędnym jest zapoznanie studentów z rozmaitymi technikami umożliwiającymi rozdzielanie mieszanin substancji. Techniki separacyjne, a szczególnie techniki chromatograficzne są dzisiaj najczęściej stosowanymitechnikami laboratoryjnymi, żadne współczesne laboratorium chemiczne czy biochemiczne nie może się bez nich obejść. Studenci będą zapoznawali się z technikami takimi, jak: współczesna chromatografia cieczowa, kapilarna...
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Comparison of Two Methods for the Determination of Selected Pesticides in Honey and Honeybee Samples
PublikacjaDeveloped and validated analytical methods for the determination of a wide spectrum of pesticide residues in honey and honeybee samples after the modification of QuEChERS extraction in combination with gas chromatography–tandem quadrupole mass spectrometry (GC-MS/MS) and liquid chromatography–tandem quadrupole mass spectrometry (LC-MS/MS) were discussed and compared. The developed methods were evaluated regarding the utilized equipment...
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Troubleshooting of the determination of bisphenol A at ultra-trace levels by liquid chromatography and tandem mass spectrometry
PublikacjaDetermination of trace amounts of bisphenol A (BPA) may cause problems mainly related to the presence of BPA in solvents (even in LC-MS grade), laboratory vessels, and plastic equipment used for sample preparation. Variable and sometimes significant amounts of BPA present in the background cause problems in obtaining good repeatability of measurements at the ultra-trace levels. Such observations (i.e., poor repeatability of results)...
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Rapid Characterization of the Human Breast Milk Lipidome Using a Solid-Phase Microextraction and Liquid Chromatography-Mass Spectrometry-Based Approach.
PublikacjaHuman breast milk (HBM) is a biofluid consisting of various biomolecules such as proteins, lipids, carbohydrates, minerals and bioactive substances. Due to its unique and complex composition, HBM provides not only nutritional components required for the growth of the infant, but also additional protection against infections. Global insight into the composition of HBM is crucial to understanding the health benefits infants receive...
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Investigation of the C-1311 glucuronidation: an electrochemical approach
Dane BadawczeThis study was undertaken to investigate the glucuronidation of the compound C-1311 (5-diethylaminoethylamino-8-hydroxyimidazoacridinone – the model anticancer acridine derivative) using electrochemistry/mass spectrometry (EC/MS) as a complementary technique to in vitro (liver microsomes) and in silico approaches.
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Rapid ion-exchange matrix removal for a decrease of detection limits in the analysis of salt-rich reservoir waters for fluorobenzoic acids by liquid chromatography coupled with tandem mass spectrometry
PublikacjaA matrix removal procedure with ion-exchange resin prior to analysis for 18 fluorinated benzoic acids (FBAs) tracers in saline (>25% salt) reservoir water was optimized. The elimination of >98% of salt and the simultaneous matrix sample cleanup allowed the direct analysis using the supernatant by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). This resulted in a gain in detection limits for most of the tracers...
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3-Monochloropropane-1,2-diol in Infant Foods and Human Breast Milk: Determination by GC-MS
Publikacja3-Monochloropropane-1,2-diol is one of the food borne contaminants called chloropropanols. Over the last decade plenty of analytical methods was developed in order to determine 3-monochloropropane-1,2-diol in its free and bound form in various foodstuffs with the use of GC-FID, GC-ECD, LC-TOFMS and finally GC-MS, which is now widely used in laboratories. The aim of this research was the determination of 3-monochloropropane--1,2-diol...
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Abuse or contamination? Ratio determination of clenbuterol enantiomers to distinguish between doping use and meat contamination
PublikacjaClenbuterol has been detected in urine of several athletes during routine doping control in the past years. Athletes claimed that the clenbuterol was ingested by eating contaminated meat. Providing analytical prove for this claim is difficult. clenbuterol consists of two enantiomers, R(-) and S(+)-clenbuterol. Currently available human and veterinary preparations were found to consist of a racemic mixture of both enantiomers. When...
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Phototransformation of three selected pharmaceuticals, naproxen, 17α-Ethinylestradiol and tetracycline in water: Identification of photoproducts and transformation pathways
PublikacjaTransformation products (TPs) may be formed during various processes, however, it was proved that one of the main mechanisms responsible for degradation of pharmaceuticals in natural waters is photolysis. Three compounds were selected, tetracycline (TC), 17-α-ethinylestradiol (EE2) and naproxen (NAP), for degradation experiments which were performed using a xenon lamp emitting light with a spectrum closely approximating that of...
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Determination of Butyltin Species in Sea Water Samples Using Solid Phase Extraction Followed by Liquid Chromatography - Tandem Mass Spectrometry
PublikacjaReverse phase liquid chromatography (RP-HPLC)-electrospray ionization-tandem mass spectrometry (ESI-MS-MS) was evaluated for the analysis of TBT using solid phase extraction as sample preparation method. TBT was extracted from acidified water samples (spiked with tripropyltin as internal standard) using reversed phase polymeric Strata-X cartridges. Analytes were eluted from cartridges using acetonitrile-water mixture and the volume...
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Profiling of polar ionogenic metabolites in Polish wines by capillary electrophoresis-mass spectrometry
PublikacjaThe composition of wine is determined by a complex interaction between environmental factors, genetic factors (i.e., grape varieties), and winemaking practices (including technology and storage). Metabolomics using NMR spec-troscopy, GC-MS, and/or LC-MS has shown to be a useful approach for assessing the origin, authenticity, and quality of various wines. Nonetheless, the use of additional analytical techniques with complementary...
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Isolation of xanthone and benzophenone derivatives from Cyclopia genistoides (L.) Vent. (honeybush) and their pro-apoptotic activity on synoviocytes from patients with rheumatoid arthritis
PublikacjaA fast and efficient method for the isolation of the C-glucosidated xanthones mangiferin and isomangiferin from the South-African plant Cyclopia genistoides was developed for the first time. Two benzophenone derivatives: 3-C-β-glucosides of maclurin and iriflophenone, were isolated from C. genistoides extracts using semi-preparative. The structures of the compounds were determined by 1D and 2D NMR experiments and/or LC-DAD-ESI–MS.
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Bezpośrednia analiza próbek z wykorzystaniem techniki spektrometrii mas. Cz. II. Technika PTR – MS – ciekawe rozwiązanie metodyczne w zakresie spektrometrii mas
PublikacjaTechnika spektrometrii mas stanowi niezwykle istotne narzędzie badawcze, umożliwiające uzyskanie wielu cennych informacji, dotyczących składu chemicznego wielu próbek rzeczywistych pochodzenia biologicznego, farmaceutycznego i spożywczego. Spektrometr mas zazwyczaj pełni role detektora w przypadku stosowania połączenia z urządzeniami chromatograficznymi (GC, LC). Dzięki zastosowaniu pewnych modyfikacji aparaturowych i metodycznych,...
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Pozostałości farmaceutyków w środowisku - problem daleki od rozwiązania
PublikacjaDo środowiska dostaje się coraz więcej związków pochodzenia farmaceutycznego. Zainteresowanie nimi tym bardziej wzrasta ze względu na ich niekorzystny wpływ nie tylko na środowisko, ale także na organizm ludzki. Mogą one powodować m.in. feminizację samców, wzrost odporności bakterii na antybiotyki oraz wzrost lekooporności ludzi. Dodatkowo farmaceutyki mogą przekształcać się w inne związki, których potencjał wywoływania efektów...
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Involvement of human glutathione S-transferase M1-1 in the glutathione conjugation of the antitumor unsymmetrical bisacridine derivative C-2028.
Dane BadawczeUnsymmetrical bisacridines (UAs) are a novel potent class of antitumor-active therapeutics. The aim of this study was to investigate the possible role of human glutathione S-transferase M1-1 (hGSTM1-1) in the glutathione (GSH) conjugation of a representative UA, C‑2028.
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Pesticide residues levels in honey from apiaries located of Northern Poland
PublikacjaConcentration levels of 30 pesticide residues were measured in honey samples collected from apiaries in northern part of Poland (Pomerania) using method based on the QuEChERS extraction followed by liquid chromatography-tandem mass spectrometry with electron spray ionization (LC-ESI-MS/MS). In 29% of the samples were found positive for at least some of the target compounds. Concentration of bifenthrin, fenpyroximate, methidathion,...
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Opracowanie metodyk oznaczania zawartości substancji farmaceutycznych w próbkach środowiskowych
PublikacjaW pracy przedstawiono wyniki badań dotyczących możliwości wykorzystanie różnych technik ekstrakcji kokcydistatyków (na przykładzie robenidyny) z próbek pasz zwierzęcych. Oznaczenia analitu wykonano z wykorzystaniem techniki HPLC - DAD - MS. Uzyskane wyniki pozwaliły nie tylko ocenić efektywność poszczególnych technik ekstrakcji robenidyny z próbek pasz zwierzęcych lecz również przeprowadzić pełną ocenę statystyczną uzyskanych wyników....
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A study on the protection of methionine and the reduction of methionine sulfoxide in methionine-containing analogues of the growth-modeling factor Gly-His-Lys
PublikacjaThe protection of methionine and the reduction of methionine sulfoxide in methionine-containing analogues of Gly-His-Lys are described. The peptides were synthesized by a solid-phase method using the standard Fmoc procedure. Simultaneous deprotection of the peptide side chain and liberation from the resin were achieved using an appropriate TFA cocktail. The TFA cocktail was selected to minimize oxidation of the methionine residue....
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Prediction of Overall In Vitro Microsomal Stability of Drug Candidates Based on Molecular Modeling and Support Vector Machines. Case Study of Novel Arylpiperazines Derivatives
PublikacjaOther than efficacy of interaction with the molecular target, metabolic stability is the primary factor responsible for the failure or success of a compound in the drug development pipeline. The ideal drug candidate should be stable enough to reach its therapeutic site of action. Despite many recent excellent achievements in the field of computational methods supporting drug metabolism studies, a well-recognized procedure to model...
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Determination of Glycerol, Propylene Glycol, and Nicotine as the Main Components in Refill Liquids for Electronic Cigarettes
PublikacjaRefill liquids for electronic cigarettes are an important area of research due to the health safety and quality control of such products. A method was developed for the determination of glycerol, propylene glycol, and nicotine in refill liquids using liquid chromatography, coupled with tandem mass spectrometry (LC-MS/MS) in multiple reaction monitoring (MRM) mode with electrospray ionisation (ESI). Sample preparation was based...
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Analytical procedures for the determination of surfactants in environmental samples
PublikacjaBecause of their specific physical and chemical properties (amphiphilicity, solubility in polar and nonpolar liquids, ability to form micelles, adsorption at phase boundaries, low toxicity) surfactants (surface-active compounds) are widely applied in industry and in the household. As their applications are on a very large scale, it has become necessary to acquire a more detailed understanding of their environmental fate.In the...
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Comparison of classical and modern approach of determination of highly polar compounds by High Performance Liquid Chromatography coupled with Tandem Mass Spectrometry
PublikacjaAbstract: Sugars and sugar alcohols are known as highly polar compounds. Four analytes were taken into consideration for comparison of classical and modern approach of separation of highly polar substances. Mannitol was chosen as an example of simple sugar alcohol, sucrose and lactulose as examples of disaccharides and structural isomers, raffinose as an example of complex trisaccharide. Raffinose was also used as internal standard...
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Rapid method for the determination of organochlorine pesticides and PCBs in fish muscle samples by microwave-assisted extraction and analysis of extracts by GC-ECD
PublikacjaA procedure for the multiresidue determination of organochlorine pesticides and polychlorinated biphenyls in fish muscle samples has been developed. The method is based on the microwave-assisted extraction (MAE) of food samples from an acetonitrile-water (95 + 5, v/v) mixture followed by SPE cleanup of the extracts and analysis by GC with an electron capture detector. MAE operational parameters, such as the extraction solvent,...
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Consequences of New Approach of Chemical Stability Tests of Active Pharmaceutical Ingredients (APIs)
PublikacjaThere is a great need of broaden look on stability tests of active pharmaceuticalingredients (APIs) in comparison with current requirements contained in pharmacopeia.By usage of many modern analytical methods the conception of monitoring the changesof APIs during initial stage of their exposure to harmful factors has been developed. Newknowledge must be acquired in terms of identification of each degradation...
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Comprehensive determination of flavouring additives and nicotine in e-cigarette refill solutions. Part II: Gas-chromatography–mass spectrometry analysis
PublikacjaFlavouring compounds are an essential part of e-liquid products for cigarettes. In general, they are regarded as safe for ingestion, but they may have unrecognized risks when they are inhaled. In some cases, manufactures do not currently abide by the Tobacco Products Directive (2014/40/EU) and do not declare the detailed contents of e-liquids on their labels. To help evaluate the health impact of flavouring substances, there is...
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Bisphenols and their derivatives in baby diaper samples.
PublikacjaMany common products contain and leach hazardous chemicals, including endocrine-disrupting chemicals such as bisphenols that are harmful to human health. For toddlers, this dangerousness is higher because of their not fully developed detoxification system. Due to this, bisphenols content in products such as baby diapers, should be monitored. Baby diapers not only remain in close contact with the skin, but are also used from the...
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Żółte barwniki organiczne w XIX-wiecznych farbach Jana Matejki - identyfikacja substancji barwiących, nośników, oraz wypełniaczy
PublikacjaNaturalne barwniki organiczne można znaleźć w wielu obiektach dziedzictwa kulturowego. Identyfikacja substancji barwiących obecnych w farbach historycznych dostarcza istotnych informacji dla wielu specjalistów zaangażowanych w naukę o sztuce. Identyfikacja składu farb pozwala na zastosowanie odpowiednich procedur dotyczących renowacji i konserwacji historycznych dzieł sztuki. Informacje te pozwalają na ich renowację zgodnie z decyzjami...
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Application of gas chromatography to the analysis of spirit-based alcoholic beverages
PublikacjaSpirit-based beverages are alcoholic drinks, which production processes are dependent on the type and origin of raw materials. The composition of this complex matrix is difficult to analyze and scientists commonly choose a gas chromatography techniques for this reason. With a wide selection of extraction methods and detectors it is possible to provide qualitative and quantitative analysis for many chemical compounds with a various...
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Quechers sample preparation method variants for analysis of pesticide residues in fruits and vegetables
PublikacjaThis article describes the comparison of different versions of an easy, rapid and low-cost sample preparation approach for the determination of pesticide residues in fruits and vegetables by concurrent use of gas and liquid chromatography coupled to MS or ECD for detection. The sample preparation approach is known as QuEChERS, which stands for quick, easy, cheap, effective, rugged and safe. It is a combination of liquid-liquid...
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Degradation kinetics and mechanism of pentoxifylline by ultraviolet activated peroxydisulfate
PublikacjaDegradation of pentoxifylline (PTX) by sodium peroxydisulfate (SPDS) assisted by UV irradiation has been investigated in deionized water. The treatment was more favorable over direct photolysis or peroxydisulfate oxidation alone. The effects of various parameters, including different dosage of oxidant agent, PTX concentration, initial solution pH levels, and the presence of inorganic ions like chloride, nitrate and carbonate have...
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Electrochemical simulation of metabolic reduction and conjugation reactions of unsymmetrical bisacridine antitumor agents, C-2028 and C-2053
PublikacjaElectrochemistry (EC) coupled with analysis techniques such as liquid chromatography (LC) and mass spectrometry (MS) has been developed as a powerful tool for drug metabolism simulation. The application of EC in metabolic studies is particularly favourable due to the low matrix contribution compared to in vitro or in vivo biological models. In this paper, the EC(/LC)/MS system was applied to simulate phase I metabolism of the representative...
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Exposure scenario and risk assessment of infants and newborns to bisphenols and their derivatives from diapers
PublikacjaNewborns and infants are more sensitive to harmful compounds such as bisphenols and their derivatives because of their not fully developed detoxification mechanism. Exposure to these substances can lead to developmental problems and health consequences in adulthood. Since disposable baby diapers are used from the first days of life and remain in contact with the baby skin, it seems important to monitor the levels of endocrine disrupting chemicals...
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5-Bromo-2′-deoxycytidine—a potential DNA photosensitizer
PublikacjaA double-stranded oligonucleotide, 80 base pairs in length, was multiply labeled with 5-bromo-2′-deoxycytidine (BrdC) using polymerase chain reaction (PCR). The modified oligonucleotide was irradiated with 300 nm photons and its damage was assayed by employing DHPLC, LC-MS and denaturing polyacrylamide gel electrophoresis (PAGE). Two types of damage were demonstrated, namely, single strand breaks (SSBs) and intrastrand cross-links...
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New approach based on solid-phase extraction for the assessment of organic compound pollutions in so-called pharmaceutically pure water
PublikacjaOpisano mozliwość zastosowania nowej procedury analitycznej opartej na wykorzystaniu techniki ekstrakcji do fazy stałej (na etapie izolacji i wzbogacania analitów) do oznaczania śladowych ilości zanieczyszczeń organicznych w wodzie specjalnej czystości używanej do celów farmaceutycznych.Próbka badanej wody jest przepuszczana przez złoże sorbenta, które jest osuszane za pomocą strumienia oczyszczonego powietrza, przed etapem termicznej...
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Nowe metody do badań składników obcych w miodach pszczelich
PublikacjaPszczoły, zbierając nektar, pyłek kwiatowy i spadź narażone są na częsty kontakt ze szkodliwymi substancjami (stosowanymi w rolnictwie) osadzonymi na roślinach i przenoszą te zanieczyszczenia - na powierzchni ciała lub wraz z pożytkami - do ula, i w konsekwencji zanieczyszczenia przedostają się do miodu.W związku z możliwością zanieczyszczenia miodu przez pestycydy należące do różnych klas związków chemicznych, pomocne okazuje...
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Comparative Lipidomic Study of Human Milk from Different Lactation Stages and Milk Formulas
PublikacjaIn this report, we present a detailed comparison of the lipid composition of human milk (HM) and formula milk (FM) targeting different lactation stages and infant age range. We studied HM samples collected from 26 Polish mothers from colostrum to 19 months of lactation, along with FM from seven brands available on the Polish market (infant formula, follow-on formula and growing-up formula). Lipid extracts were analysed using liquid...
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Influence of Diosmin Treatment on the Level of Oxidative Stress Markers in Patients with Chronic Venous Insufficiency
PublikacjaOxidative stress plays an important role in the pathophysiology of many human disorders, while antioxidants prevent the development of various adverse symptoms. Diosmin is a natural flavonoid applied in vascular system disorders, especially in chronic venous insufficiency (CVI), and it plays a significant part in the alleviation of CVI symptoms. Due to antioxidant activity, it also has the ability to scavenge the oxygen free radicals...
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X-ray and UV Radiation Damage of dsDNA/Protein Complexes
PublikacjaRadiation and photodynamic therapies are used for cancer treatment by targeting DNA. However, efficiency is limited due to physico-chemical processes and the insensitivity of native nucleobases to damage. Thus, incorporation of radio- and photosensitizers into these therapies should increase both efficacy and the yield of DNA damage. To date, studies of sensitization processes have been performed on simple model systems, e.g.,...
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Selected concentration techniques for gas chromatographic analysis of environmental samples
PublikacjaThe paper describes the role and tasks of environmental analysis and monitoring. It emphasises the leading role played by gas chromatography, especially when coupled with suitable sample preparation. This is demonstrated by some literature evidence and mainly by the author's original work on the design of sample preparation apparatus and development of GC-based methods of determination of a wide variety of organic pollutants in...
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Comprehensive methodology for Staphylococcus aureus lipidomics by liquid chromatography and quadrupole time-of-flight mass spectrometry
PublikacjaStaphylococcus aureus is a common pathogen known to cause relatively minor infections as well as severe disorders in humans. Although there is fair amount of published data concerning various aspects of its biology, epidemiology, genetics, etc., there is still a scarce amount of data presenting reliable and thorough investigations regarding high-throughput analysis of total S. aureus lipid content. Therefore, the aim of this study...