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1

Protein profiles from intact cells as a tool in Bifidobacterium characteristics

100%
Wasko A., Polak-Berecka M., Kalita M.
Polish Journal of Microbiology
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2012
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tom 61
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nr 4
In this study sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) profiles were analysed and differences were confirmed by a unweighted pair group method with arithmetic average (UPGMA) analysis between bifidobacterial species, such as B. infanis ATCC1567, B. bifidum Bb-12, B. longum KN29, B. catenulatum KD14, and B. animalis BI30. Two dimensional electrophoresis separation profiles were compared, and the most characteristic spots were characterized by liquid chromatography-tandem mass spectrometry (LC-MS/MS). We propose proteins extracted from intact cells as an additional trait for bifidobacteria characterization, together with molecular techniques, which can be used to analyze bacterial protein polymorphism and to distinguish among species.
2
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Determination of chloramphenicol in milk powder using liquid-liquid cartridge extraction (Chem Elut) and liquid chromatography-tandem mass spectrometry

86%
Zawadzka I., Rodziewicz L.
Roczniki Państwowego Zakładu Higieny
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2014
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tom 65
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nr 3
Background. The European Union prohibits the use of chloramphenicol (CAP) as a veterinary drug in food-producing animals. Nevertheless, CAP have been detected in milk products (liquid milk and milk powder). Therefore, it is necessary to develop sensitive methods for determining CAP residues in milk powder. Objective. The aim of this study was to develop and validate a confirmatory method for determination of CAP in milk powder. Material and methods. Chloramphenicol was determined in milk powder using LC-ESI-MS/MS in negative mode. After fat removing milk powder sample was extracted/cleaned-up with a Chem Elut extraction cartridge. Separation was achieved on a Phenomenex Luna C-18 column with acetonitrile-water as a mobile phase. The mass spectrometer was operated in multiple reaction monitoring mode (MRM). Four transitions were monitored m/z 321→152, 321→194, 321→257 (CAP) and 326→157 (IS CAP-d5). Results. Linearity, accuracy, precision, decision limit (CCa), detection capability (CCb) and ruggedness were determined for m/z 321→152. The mean relative recoveries (inter standard-corrected) of CAP from whole milk powder spiked at levels 0.1, 0.2, 0.3 and 0.6 mg/kg were in the range 95 - 103%. Relative standard deviation (RSD%) of recoveries at all spiked levels were less than 14%. RSDs within-laboratory reproducibility calculated at fortification of 0.3 mg/kg was less than 16%. CCa and CCb were below 0.1 mg/kg. Conclusions. The developed LC-MS/MS method allows the determination of CAP in milk powder. The method was validated according to the Commission Decision No. 2002/657/EC requirements. This method can be applied to determination CAP in whole and skim milk powder.
3
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LC-MS/MS analysis of phenolic compounds and in vitro antioxidant potential of Stachys lavandulifolia Vahl.var. brachydon Boiss

86%
Bingol M. N., Bursal E.
International Letters of Natural Sciences
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2018
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tom 72
The identification and quantification of phenolic compounds of Stachys lavandulifolia Vahl. var. brachydon Boiss. by LC-MS/MS (Liquid Chromatography- tandem Mass Spectrometry) technique is the main purpose of the current study. The high concentrations of quinic acid (2534± 12 ppb) and chlorogenic acid (1882±92 ppb) were detected by LC-MS/MS.. Another goal of the study is to evaluate the antioxidant activities of both ethanol and aqueous extracts of the plant material. The antioxidant potentials of extracts were determined by using five different in vitro methods including; ABTS (2,2′-Azino-bis-3-ethylbenzothiazoline-6-sulfonic acid), DPPH(1,1- diphenyl-2-picryl-hydrazyl), FRAP (Ferric ions Reducing Antioxidant Power), CUPRAC (Cupric ions Reducing Antioxidant Power), and ferric thiocyanate methods. The results revealed that the aqueous and ethanol extracts of S. lavandulifolia leaves have good antioxidant potential with high phenolic content.
4

Procedure of determination of multiresidue pesticides in honey based on acetonitrile extraction and liquid chromatography-tandem mass spectrometry

72%
Barganska Z., Slebioda M., Namiesnik J.
Polish Journal of Food and Nutrition Sciences
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2011
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tom 61
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nr Suppl.1
5
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Development and validation of a new method for determining nitrofuran metabolites in bovine urine using liquid chromatography - tandem mass spectrometry

72%
Rodziewicz L., Zawadzka I.
Roczniki Państwowego Zakładu Higieny
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2013
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tom 64
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nr 4
Background. The use of nitrofurans as veterinary drugs in food-producing animals is banned throughout the European Union. Nevertheless, nitrofuran metabolites have been detected not only in animal products, but also in bovine urine. At present there are no methods yet published for the simultaneous detection of nitrofuran metabolites in bovine urine. Objectives. To develop and validate a method for determination of four key nitrofuran metabolites in bovine urine. Material and methods. The four nitrofuran metabolites (nitrofurantoin, furazolidone, nitrofurazone and furaltadone), were determined in bovine urine using LC-ESI-MS/MS. The procedure required an acid-catalysed release of protein-bound metabolites, followed by their in situ conversion into 2-nitrobenzaldehyde (NBA) derivatives. The sample clean-up was performed using a polymer extraction cartridge before hydrolysis. Nitrofuran metabolites were then determined using electrospray ionization in the positive mode, that had previously been separated on a Phenomenex Luna C-18 column. Results. The method was validated in accordance with the procedure outlined in the Commission Decision No. 2002/657/ EC. Urine samples were spiked with nitrofuran metabolite solutions at levels of 0.5, 1.0, 1.5 and 2.0 pg/kg. Recoveries ranged between 90 - 108% (inter standard-corrected), with a repeatability precision (RSD) of less than 19% for all four analytes. The decision limit (CC) and detection capability (DC) were obtained from a calibration curve and lay respectively within the following ranges: 0.11- 0.34 pg/kg and 0.13- 0.43 pg/kg. Conclusions. The developed and validated LC-ESI-MS/MS method allows four nitrofuran metabolites to be identified and quantitated in bovine urine. This analytical procedure meets the criteria defined in the Commission Decision No. 2002/657/EC.
6

Evaluation of the effect of surgical and immunological castration of male pigs on boar taint compounds in oral fluid and fat tissue by LC-MS/MS method

72%
Wozniak B., Cybulski P., Jablonski A., Witek S., Matraszek-Zuchowska I.
Journal of Veterinary Research
|
2020
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tom 64
|
nr 4
7
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Bioactive metabolites produced by Spirulina subsalsa from the Baltic Sea

72%
Szubert K., Wiglusz M., Mazur-Marzec H.
Oceanologia
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2018
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tom 60
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nr 3
8

Effect of Medicago sativa Mhb1 gene expression on defense response of Arabidopsis thaliana plants

58%
Maassen A., Hennig J.
Acta Biochimica Polonica
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2011
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tom 58
|
nr 3
Besides the previouly described nitric oxide-detoxification activity we identified new features of class-1 non-symbiotic hemoglobin from Medicago sativa (Mhb1). Under in vitro conditions, using peroxidase in-gel activity assay, the Mhb1 protein was shown to possess also peroxidase-like activity. Due to this activity, in the presence of nitrite and hydrogen peroxide, the protein can mediate autonitration and nitration of other proteins at tyrosine residues, as revealed by tandem mass spectrometry and immune assay approaches. Mhb1 through its multifunctional activities can affect different components of signal transduction cascades operating during plant response to infections. This influence is manifested by Mhb1-mediated selective up-regulation of expression of certain pathogen inducible genes in Pseudomonas syringae infected Arabidopsis thaliana plants which overproduce Mhb1, as revealed by reverse transcription-quantitative real-time PCR analysis. Changes in expression level of these genes can influence such processes as synthesis of secondary metabolites, protein degradation and biosynthesis of ethylene. They can also result in alteration of pathogen-induced defense response of Mhb1 transgenic plants.
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