Wyniki wyszukiwania - Biblioteka Nauki

1

Study of CO2 clusters by mass spectrometry

100%

Dąbek J. , Michalak L.

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1999

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tom Vol. 44, nr 2

293-298

EN

The beams of (CO2)n cluster ions (n=2-18) are studied by the adiabatic nozzle expansion of CO2 and subsequent ionization by the electron impact. They are analysed in a double focussed sector field mass spectrometer. In the case of 70 eV electron energy four homologous series of ions can be identified in the mass spectrum.

PL

Wiązki klasterów (CO2)n (n=2-18) wytwarzano metodą adiabatycznego wypływu CO2 z dyszy. Zjonizowane klastery były analizowane przy użyciu podwójnie ogniskującego, sektorowego spektrometru mas. Przy energii elektronów równej 70eV, zarejestrowano cztery serie jonów, w tym jony klasterów oraz jony ich homologów.

2

Detection and sequencing of new cyclic peptides from linseed by electrospray ionization mass spectrometry.

100%

Stefanowicz P.

Acta Biochimica Polonica

|

2001

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tom 48

|

nr 4

1125-1129

EN

Extract of Linum usitatissimum seeds was analyzed by ESI-MS and ESI-MS/MS. The analysis confirms the presence of previously reported cyclolinopeptides: CLA (c(Pro-Pro-Phe-Phe-Leu-Ile-Ile-Leu-Val) and CLB (c(Pro-Pro-Phe-Phe-Val-Ile-Met-Ile-Leu)). Cyclolinopeptides CLD and CLE, which contain methionine oxide, were detected in small quantities only. These peptides likely result from the oxidation of their precursors, not reported previously: CLD' (c(Pro-Phe-Phe-Trp-Ile-Met-Leu-Leu)) and CLE' (c(Pro-Leu-Phe-Ile-Met-Leu-Val-Phe)), present at higher concentrations in unoxidized extract. Two new cyclic octapeptides: CLF (c(Pro-Phe-Phe-Trp-Val-Met-Leu-Met)) and CLG (c(Pro-Phe-Phe-Trp-Ile-Met-Leu-Met)) were detected and their sequences were proposed on the basis of CID experiments and similarity with those of CLD'.

3

Preparation, Separation and Identification of Some para-Substituted ONN and NNO trans-Azoxybenzenes

80%

Domański A. A. , Kyzioł J. B.

|

2001

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tom Vol. 75, nr 12

1839-1846

EN

A series of para-substituted azoxybenzenes was obtained as model compounds for the investigation on the mechanism of Wallach rearrangement. Oxidation of azobenzenes with hydrogen peroxide in acetic acid solution, provided mixtures of alfa and beta isomers. Some couples of the products were separated, using chromatography and crystallization techniques, and identifiedon the basis of their carbon NMR and mass spectra. The SCSDal-gorithm can be applied to the interpretation of the I3C-NMR spectra. Recognition of the ipso andpara carbons suffice to the identification of an isomer, hence there are no strong interactions between the azoxy group and another substituent across the aromatic ring. Fragmentation of azoxybenzenes under electron impact occurs preferentially on the oxidized side of the azoxy bridge. Relative intensities of daughter ions differentiate the ONN = a. and NNO = P isomers in most cases.

4

FAPA mass spectrometry of hydroxychalcones. Comparative studies with classical methods of ionization

80%

Smoluch M. , Bartkowiak G. , Reszke E. , Lechowicz W. , Silberring J. , Schroeder G.

Current Issues in Pharmacy and Medical Sciences

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2014

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tom 27

|

nr 1

27-31

EN

In this paper we are focused on analysis of hydroxychalcones, i.e. 2’-hydroxychalcone, 3’-hydroxychalcone and 4’-hydroxychalcone, by the Flowing Atmospheric Pressure Afterglow mass spectrometry (FAPA-MS), and on comparison of the obtained data with other classical methods including ESI-MS, APCI, MALDI, and GC/EI-MS. The paper is presenting fragmentation pathways of both positive-, and negative hydroxychalcone ions. Tested compounds were characterized by comparison of the results (signals m/z and relative intensities) from the five mass spectrometry techniques, showing very good utility of FAPA method for fast and easy analysis of the low molecular weight compounds. Moreover, FAPA does not require a time-consuming derivatization, nor search for a suitable solvent or matrix, often incompatible with various ion sources.

5

Mass spectrometry of some derivatives of 5-(indol-2-yl)pyrimidine

80%

Celewicz L. , Frański R. , Urjasz H. , Płaziak A. S.

|

1998

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tom Vol. 72, nr 4

725-734

EN

The electron impact (EI) and liquid secondary ion (LSI) mass spectra of 5-(indol-2--yl)pyrimidine derivatives are discussed. It was established that 5-(indol-2--yl)uracils, instead of the cleavage of the single carbon-carbon bond between uracil and indole ring, form stable ions with additional linkage between 4O-oxygen of uracil and CH2 group at the 3 position of indole moiety. Similarly, 5-(indol-2-yl)cytosines yield stable tetracyclic ions with new linkage between 4N-nitrogen of cytosine and CH2 group at the 3 position of indole ring.

6

Metabolism of bradykinin in aorta of hypertensive rats

80%

Bujak-Giżycka B. , Olszanecki R. , Madej J. , Suski M. , Gębska A. , Korbut R.

Acta Biochimica Polonica

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2011

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tom 58

|

nr 2

199-202

EN

Alterations in the formation and metabolism of bradykinin (Bk) are hypothesized to play a role in the pathophysiology of hypertension, atherosclerosis and vascular complications of diabetes. However, despite its prominent role in cardiovascular regulation, studies on bradykinin have been limited by various difficulties in accurate measurements of this peptide in biological samples. In this study, using the LC-ESI-MS method we estimated the conversion of exogenous Bk to its main metabolites - Bk-(1-5) and Bk-(1-7) - in endothelial cell culture and in fragments of aorta of normotensive (WKY) and hypertensive rats (SHR). The effects of angiotensin converting enzyme (ACE) and neutral endopeptidase (NEP) inhibitors were more pronounced in SHR: perindoprilat inhibited Bk-(1-5) formation by 49 % and 76 % in WKY and SHR rats, respectively, and tiorphan tended to decrease formation of Bk-(1-5) in both groups of animals. The degradation of bradykinin and generation of both metabolites were significantly higher in the aorta of SHR rats than in WKY controls. Our results show that even in relatively early hypertension (in 4-month old SHR rats) inactivation of Bk by aorta wall is enhanced.

7

Single particle analysis of soil dust by aerosol time-of-flight laser mass spectrometry

80%

Xiao-Yong Guo X.-Y. , Wen-Wu Zhao W.-W. , Ming-Qiang Huang M.-Q. , Hai-Yang Zheng H.-Y. , Li Fang L. , Wei-Jun Zhang W.-J.

|

2007

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tom Vol. 37, nr 3

229-235

EN

A laboratory study was carried out to investigate the single particle soil dust using aerosol time-of-flight mass spectrometry. The presence of crustal elements is observed in the mass spectra of individual particles. Potassium and iron constitute the two most commonly detected cations. Other common cations observed in the mass spectra of soil particles include sodium and magnesium. According to a large number of single aerosol diameters, we obtained the size distribution. Peaks in the positive ion mass spectra enable us to identify individual dust particles in atmospheric samples and track chemically distinct dust particles in the atmosphere using aerosol time-of-flight mass spectrometry.

8

Spektrometr mas z pomiarem czasu przelotu jonów w zakładzie fizyki stosowanej UMCS

80%

Giuch K. , Bajuk A. , Michalak L.

|

2001

|

tom nr 2-3

54-63

PL

Spektrometria mas oparta na pomiarze czasu przelotu jonów (TOF-MS Time Qf Flight Mass Spectrometry) jest obecnie szeroko stosowaną techniką ich rozdzielania. Koncepcja tego typu spektrometru zaproponowana została po raz pierwszy w 1948 roku przez A.E. Camerona. Dopiero wprowadzenie w latach 70-tych i 80-tych ubiegłego stulecia wielu udoskonaleń, zarówno w źródle jonów (zastosowanie nanosekundowych laserów) jak i optyce jonowej (zastosowanie reflektronu), uczyniło je bardzo cenionymi urządzeniami analitycznymi. Główne zalety takich spektrometrów to praktycznie nieograniczony zakres analizowanych mas, stosunkowo prosta konstrukcja oraz możliwość detekcji ciężkich molekuł. Praca przedstawia rozwiązania konstrukcyjne i parametry pomiarowe spektrometru mas z pomiarem czasu przelotu jonów zbudowanego w Zakładzie Fizyki Stosowanej Instytutu Fizyki Uniwersytetu Marii Curie-Sklodowskiej. Spektrometr ten służy do badań zjawisk jonizacyjnych metodą MALDI.

EN

Time of flight mass spectrometry (TOF-MS) is a common technique used to resolve mass difference of ions. The concept of this spectrometer was proposed first time in 1948 by A.E. Cameron. Many improvements in ion source (application of nanosecond lasers) and ions optics (application of the reflectron) at the 70's and 80's made the time of flight mass Spectrometry very useful for analytical applications. The main advantages of such systems are practically unlimited mass range, straightforward construction and possibility of high masses of molecules detection. This work presents construction and measurement parameters of the time of flight mass spectrometer built in the Division of Applied Physics, Institute of Physics, Maria Curie-Sklodowska University. This spectrometer is used for studies of ionization processes by MALDI method.

9

COCAINE CONSUMPTION IN THE CITY OF MURCIA (SOUTHEAST OF SPAIN) ESTIMATED BY WASTEWATER ANALYSIS: APPLYING AN ACCURATE AND VALID TOOL TO OBTAIN OBJECTIVE DATA FOR DRUG ABUSE.

70%

Navarro-Zaragoza J. , Fernández-López L. , Caravaca F. , Falcón M. , Luna A.

Acta Poloniae Pharmaceutica - Drug Research

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2019

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tom 76

|

nr 1

137-145

EN

Cocaine consumption is one of the most relevant public health issues in America and Europe. There are different methods to estimate cocaine consumption, with different levels of accuracy. Although surveys is one of the most employed methods, it usually underestimates cocaine consumption. Recent studies have validated the use of wastewater analysis as the method that would provide more accurate results, as it is based on the analysis of residues of illicit drugs and their metabolites that are excreted by human flow through wastewater treatment plants. This study aims to estimate cocaine consumption in the southeast of Spain by wastewater analysis. Samples were analyzed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). According to this analysis, cocaine consumption has been estimated at 410,6 milligrams per day and per 1000 inhabitants, a higher result than that obtained at other European cities of similar size. Highest consumption occurs during the weekend, which is consistent with cocaine being categorized as a recreational drug. The results of this analysis show that cocaine use is an increasing public health and economic problem. Finally, wastewater analysis offers different options to estimate its use at this region of Spain.

10

Temperature stability of mercury compounds in solid substrates

70%

Sedlar M. , Pavlin M. , Popovič A. , Horvat M.

Open Chemistry

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2015

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tom 13

|

nr 1

EN

The major aim of the newly adopted Mercury Convention is to reduce global mercury (Hg) emissions to the environment. In high temperature industrial processes, including coal combustion, Hg compounds present as impurities in solid materials are decomposed and evaporated leading to the emission of Hg to the atmosphere. The behaviour of different Hg compounds and their mixtures during heating have been the subject of numerous studies, and is the topic of the present work. Controlled heating can be used to fractionate Hg compounds in solid substrates, offering the possibility of identification and quantification of Hg compounds. In the attempt to develop a method for temperature fractionation of Hg, experiments were conducted with pure Hg compounds, and the compounds mixed with different substrates (SiO2 and CaSO4 • 2H2O), for calibration purposes. Detection was performed by two methods, namely Cold Vapour Atomic Absorption Spectrometry (CV AAS) with Zeeman background correction, and Nier-type Mass Spectrometry with a Knudsen cell (MS). Further investigation is in process.

11

Liquid chromatographic determination of glyphosate and aminomethylphosphonic acid residues in rapeseed with MS/MS detection or derivatization/fluorescence detection

70%

Kaczyński P. , Łozowicka B.

Open Chemistry

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2015

|

tom 13

|

nr 1

EN

Glyphosate and AMPA determinations in rapeseed extracts by (a) liquid chromatography with triple quadrupole MS detection (LC-MS/MS), or (b) liquid chromatography with post-column OPA derivatization and fluorescence detection (LC-FLD) were developed. Mean recoveries for glyphosate and AMPA were (a) 88.8–95.0% and 82.1–86.1%, and (b) 70.8–74.1% and 62.4–72.6%. RSD were below (a) 11% and (b) 22%. Correlation coefficients were above 0.997 for both methods. LOD were 0.01 mg kg-1 for (a) and 0.05 mg kg-1 for (b). Both methods are simple and efficient for routine analysis of glyphosate and AMPA in a fatty matrix.

12

Application of the TG-MS system in studying sewage sludge pyrolysis and gasification

70%

Bedyk T. , Nowicki L. , Stolarek P. , Ledakowicz S.

Polish Journal of Chemical Technology

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2008

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tom 10

|

nr 1

1-5

EN

A method of monitoring sewage sludge pyrolysis and gasification was proposed. Samples of sludge were pyrolysed in Ar and gasified in CO2 in a thermobalance. The evolved gases were analysed on the calibrated MS, the samples of sludge and solid residues at different stages of the processes were subjected to elemental analysis. The identification and the quantitative characterisation of chemical reactions were performed, based on the DTG and MS profiles.

13

Spektrometria mas w analizie elementarnej - tajniki procedury pomiarowej, cz. II

70%

Wojciechowski M. , Krata A. , Bulska E.

|

2008

|

tom nr 4

4-8

14

Ionizing radiation affects profile of serum metabolites: increased level of 3-hydroxybutyric acid in serum of cancer patients treated with radiotherapy

70%

Roś-Mazurczyk M. , Wojakowska A. , Marczak Ł. , Polański K. , Pietrowska M. , Jelonek K. , Domińczyk I. , Hajduk A. , Rutkowski T. , Składowski K. , Widłak P.

Acta Biochimica Polonica

|

2017

|

tom 64

|

nr 1

189-193

EN

Radiotherapy causes molecular changes observed at the level of body fluids, which are potential biomarker candidates for assessment of radiation exposure. Here we analyzed radiotherapy-induced changes in a profile of small metabolites detected in sera of head and neck cancer patients using the gas chromatography coupled with mass spectrometry approach. There were about 20 compounds, including carboxylic acids, sugars, amines and amino acids, whose levels significantly differed between pre-treatment and post-treatment samples. Among metabolites upregulated by radiotherapy there was 3-hydroxybutyric acid, whose level increased about three times in post-treatment samples. Moreover, compounds affected by irradiation were associated with several metabolic pathways, including protein biosynthesis and amino acid metabolism.

15

Physical foundations of rhenium-osmium method - a review

70%

Dąbek J. , Halas S.

Geochronometria

|

2007

|

tom Vol. 27

23-26

EN

A newly acquired mass spectrometer MI 1201 by the Mass Spectrometry Laboratory will be adapted to determine rhenium and osmium isotope concentrations using negative thermal ionization mass spectrometry (NTIMS). We describe the principle of the Re-Os dating technique and the thermal ionization phenomena which lead to high precision isotope analysis on NTIMS.

16

Mass spectrometric analysis of head-to-tail connected cyclic peptides.

70%

Macht M. , Pelzing M. , Palloch P. , Sauerland V. , Volz J.

Acta Biochimica Polonica

|

2001

|

tom 48

|

nr 4

1109-1112

EN

Tandem mass spectrometry is an extremly useful tool for high sensitive sequence identification of peptides. In the case of cyclic peptides fragmentation can easily be performed for sequence analysis. However, analysis is usually tedious due to the lack of a defined beginning and end of the sequence. Since cyclic peptides are a highly interesting class of compounds especially for the pharmaceutical industry, ways have to be found to identify their structures. In this work we demonstrate how software and dedicated analytical strategies can be used for detailed analysis of these substances.

17

Laserowa jonizacja próbki wspomagana matrycą

60%

Bajuk A. , Głuch K. , Michalak L.

|

2001

|

tom nr 4

37-46

PL

Laserowa jonizacja próbki wspomagana matrycą (MALDI - Matrix Assisted Laser Desorption/Ionization) jest nową metodą stosowaną w spektrometrii masowej od polowy lat osiemdziesiątych w badaniach ciężkich biomolekuł. Wykorzystuje ona stalą matrycę, która pełni kluczową rolę w ich procesach jonizacyjnych. Procesy te (desorpcja, jonizacja) inicjuje tutaj krótkotrwały (kilka nanosekund) impuls światła laserowego. Dzięki tzw. "miękkiej" jonizacji w metodzie MALDI znajduje ona zastosowanie w badaniach ciężkich biomolekuł takich jak peptydy, białka, kwasy karboksylowe i wiele innych. W artykule zawarte są podstawy dotyczące spektrometrii masowej związków biologicznych, a także informacje na temat procesu jonizacji za pomocą desorpcji laserowej. Ponadto zaprezentowane są wyniki najnowszych badań przeprowadzonych metodą MALDI w Zakładzie Fizyki Stosowanej Instytutu Fizyki Uniwersytetu Marii Curie-Skłodowskiej w Lublinie.

EN

MALDI (Matrix Assisted Laser Desorption and lonization) is a quite new method used in the mass spectrometry since the middle of eighties in studies of heavy biomolecules. It uses a solid matrix that is crucial in the ionization processes of macromolecular substances. These processes (desorption and ionization) are initiated by a few nanoseconds laser pulse. Because of its "softness", MALDI has the application in the analysis of biomolecules such aspeptides, proteins, carbohydrates, oligonucleodites and others. This article presents basics of the biomolecule mass spectrometry first of all, but also some general pieces of information about sample ionization processes by MALDI. Some of the results obtained by using TOF spectrometer, in the Division of Applied Physics, Institute of Physics, Marie Curie-Sklodowska University, are also presented.

18

Spektrometria mas we współczesnej analityce. Część IV: Interferencje w ICP-MS i sposoby ich eliminacji

60%

Ruszczyńska A. , Bulska E.

|

2006

|

tom nr 3

10-15

19

Badanie redukcji zawartości ołowiu i wzrostu stężenia srebra w wodzie doczyszczanej za pomocą filtrów dzbankowych techniką spektrometrii mas z plazmą indukcyjnie sprzężoną (ICP-MS)

60%

Garboś S. , Święcicka D.

|

2006

|

tom nr 11

63-65

PL

Wyroby i materiały stosowane do przesyłania, czerpania i doczyszczania wody przeznaczonej do spożycia mogą mieć istotny wpłw na pogorszenie jej jakośći pod względem zdrowotnym. W związku z tym niezbedne jest badanie np. stężeń niektórych metali w wodzie pozostającej w kontakcie z ww. urządzeniami i materiałami za pomocą odpowiednio czułych technik spektrometrii atomowej — optycznej spektrometrii emisyjnej ze wzbudzeniem w plazmie indukcyjnie sprzężonej (ICP-OES) i spektrometrii mas z jonizacją w plazrnie indukcyjnie sprzężonej (ICP-MS). Stosowanie filtrów węglowych modyfikowanych srebrem prowadzi do wzrostu stężenia srebra w doczyszczanej wodzie podczas całego cyklu ich użytkowania. Z drugiej strony filtry tego typu zawierające węgiel aktywny i/lub wymieniacze jonowe mogą przyczyniać się do efektywnej redukcji zawartości niektórych metali — na przykład ołowiu. Ma to duże znaczenie ze względu na fakt, że materiały zastosowane do konstrukcji instalacji wodnych i armatury używanej do czerpania wody wodociągowej mogą być odpowiedzialne za znaczące zwiększenie obserwowanych stężeń pierwiastkow takich jak: chrom, nikiel, miedź, cynk i ołów. Proces ich usunięcia z doczyszczanej wody jest korzystny z punktu widzenia ochrony zdrowia konsumenta.

EN

Devices and materials used for: water cleaning thoroughly - carbon filters or filters with ion exchangers, the construction of water supply and sewage system and producing the plumbing fixtures used for water drawing can have the essential influence on the deterioration of wholesome quality of water intended for human consumption. In connection with this fact it is necessary to study the concentration of some metals present in water, which is in contact with devices and materials mentioned above, using adequate sensitive methods — atomic spectrometric methods such as: inductively coupled plasma atomic emission spectrometry (ICP-AES) and inductively coupled plasma mass spectrometry (ICP-MS). The studies have shown that the application of carbon filters modified with silver has led to the increase of silver concentration in purified water during whole cycle of their usage. On the other hand such types of filters containing the activated carbon and/or ion exchange resins could be used for effective removal of some metals — for example lead. It has significant importance because the materials applied for construction the water supply systems and fittings may be responsible for considerable increase of observed concentration of several elements in tap water such as: chromium, nickel, copper, zinc and lead. Removal process of such metals from purified water is the advantage from the point of view of consumer's health protection.

20

Badania fizykochemicznych podstaw regulacji procesu azotowania jarzeniowego z wykorzystaniem diagnostyki plazmy

60%

Smolik J. , Walkowicz J. , Miernik K. , Szubrycht T.

|

2000

|

tom nr 2

335-348

PL

W artykule zostały przedstawione widma emisyjne oraz widma masowe plazmy wyładowania jarzeniowego zarejestrowane dla trzech procesów azotowania różniących się składem atmosfery azotującej i parametrami prądowo-napięciowymi wyładowania. W celu identyfikacji uzyskanych struktur warstw azotowanych wykonano badania dyfrakcyjne i metalograficzne. Na podstawie zarejestrowanych widm oraz po uwzględnieniu wyników wykonanych badań strukturalnych dla utworzonych warstw azotowanych dokonana została próba oceny, które ze składników plazmy istotnie wpływają na strukturę tworzonej warstwy azotowanej. Analiza widm masowych pozwoliła określić decydujący wpływ azotu atomowego na intensywność procesu azotowania natomiast analiza widm emisyjnych pozwoliła określić mechanizm jego wytwarzania w badanych procesach.

EN

The paper presents the mass and emission spectra of the glow discharge plasma recorded for three different processes of ion nitriding. The structures of nitrided layers were investigated with the used of X-ray diffraction and optical metallography. The paper's authors revealed the correlation between parameters of the glow discharge plasma, observed by spectroscopic methods, and kinetics of the nitriding process determined by the structures of nitrided layers. On the basis of the obtained results plasma components, decisive for forming of individual structures of the nitrided layer, during nitriding process were assigned.