Jan Krzek
Jagiellonian University Medical College
Proton NMRDerivativeAnalyteAnalytical chemistryDetection limitDensitometryIonKineticsDegradation (geology)RepeatabilityMass spectrometryPhotodegradationHigh-performance liquid chromatographyChemistryThin-layer chromatographyAcetic acidSilica gelMethanolSpectrophotometryChromatographyPhase (matter)ImpurityDosage formQuantitative analysis (chemistry)
129Publications
17H-index
1,274Citations
Publications 129
Newest
#1Urszula HubickaH-Index: 9
#2Jan KrzekH-Index: 17
Last. Agata KryczykH-Index: 5
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#1Maciej Długosz (Jagiellonian University)H-Index: 5
#2Paweł Żmudzki (Jagiellonian University Medical College)H-Index: 13
Last. Maria Nowakowska (Jagiellonian University)H-Index: 34
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Abstract Photocatalytic degradation of an antibiotic, sulfamethoxazole (SMX), in aqueous solution using a novel floating TiO 2 -expanded perlite photocatalyst (EP-TiO 2 -773) and radiation from the near UV spectral range was studied. The process is important considering that SMX is known to be a widespread and highly persistent pollutant of water resources. SMX degradation was described using a pseudo-first-order kinetic equation according to the Langmuir–Hinshelwood model. The products of the S...
104 CitationsSource
#1Mariusz Stolarczyk (Jagiellonian University Medical College)H-Index: 3
#1Mariusz Stolarczyk (Jagiellonian University Medical College)H-Index: 7
Last. Jan KrzekH-Index: 17
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A new sensitive, simple, rapid, and precise HPLC method with diode array detection has been developed for separation and simultaneous determination of hydrochlorothiazide, furosemide, torasemide, losartane, quinapril, valsartan, spironolactone, and canrenone in combined pharmaceutical dosage forms. The chromatographic analysis of the tested drugs was performed on an ACE C18, 100 A, 250×4.6 mm, 5 μm particle size column with 0.0.05 M phosphate buffer (pH=3.00)-acetonitrile-methanol (30+20+50 v/v/...
1 CitationsSource
#1Monika Dąbrowska (Jagiellonian University)H-Index: 7
#2Łukasz Komsta (Medical University of Lublin)H-Index: 14
Last. Kinga Kokoszka (Jagiellonian University)H-Index: 1
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The lipophilicity (RM0) and specific hydrophobic surface area for the representatives of four generation cephalosporins have been determined by reversed-phase thin-layer chromatography, and the effect of different mobile-phase modifiers (such as methanol, acetonitrile, acetone, 1,4-dioxane and 2-propanol) on the retention has been studied. The compounds studied showed typical retention behavior; their RM values decreased linearly with increasing concentration of the organic modifier in the eluen...
11 CitationsSource
#1Mariusz Stolarczyk (Jagiellonian University Medical College)H-Index: 7
#1Mariusz Stolarczyk (Jagiellonian University Medical College)H-Index: 3
Last. Jan Krzek (Jagiellonian University Medical College)H-Index: 17
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Abstract Fast, accurate and precise method for the determination of zofenopril and fluvastatin was developed using spectrophotometry of the first (D1), second (D2), and third (D3) order derivatives in two-component mixtures and in pharmaceutical preparations. It was shown, that the developed method allows for the determination of the tested components in a direct manner, despite the apparent interference of the absorption spectra in the UV range. For quantitative determinations, “zero-crossing” ...
1 CitationsSource
#1Irena Smaga (Jagiellonian University Medical College)H-Index: 13
#2Ewa Niedzielska (Jagiellonian University Medical College)H-Index: 8
Last. Małgorzata Filip (PAN: Polish Academy of Sciences)H-Index: 20
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Abstract The pathophysiology of psychiatric diseases, including depression, anxiety, schizophrenia and autism, is far from being fully elucidated. In recent years, a potential role of the oxidative stress has been highlighted in the pathogenesis of neuropsychiatric disorders. A body of clinical and preclinical evidence indicates that psychiatric diseases are characterized by higher levels of oxidative biomarkers and with lower levels of antioxidant defense biomarkers in the brain and peripheral ...
142 CitationsSource
#1Andrzej Moniczewski (Jagiellonian University Medical College)H-Index: 11
#2Maciej Gawlik (Jagiellonian University Medical College)H-Index: 4
Last. Małgorzata Filip (Jagiellonian University Medical College)H-Index: 20
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Oxidative stress is a dysfunctional state of living cells, caused by the disturbance of the pro-/antioxidative equilibrium. This dynamic equilibrium, constitutive for all aerobic organisms, is an inevitable necessity of maintaining the level of oxidative factors on non-destructive value to the cell. Among these factors reactive oxygen species (ROS) and reactive nitrogen species (RNS) are the best known molecules. This review article shows the current state of knowledge on the chemical specificit...
39 CitationsSource
#1Mariusz Stolarczyk (Jagiellonian University Medical College)H-Index: 7
#1Mariusz Stolarczyk (Jagiellonian University Medical College)H-Index: 3
Last. Jan Krzek (Jagiellonian University Medical College)H-Index: 17
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According to data from the World Health Organization, cardiovascular diseases are the most common diseases of the 21st century. They are the reason for about 17 million deaths each year, including 9.4 million deaths caused by hypertensive disease or complications occurring during its course [http://www.thehealthwell.info/node/466541]. Therapeutic schemes in arterial hypertension include monotherapy or combination therapy involving administration of two or three drugs from various pharmacological...
2 CitationsSource
#1Małgorzata Starek (Jagiellonian University Medical College)H-Index: 12
#2Anna Guja (Jagiellonian University Medical College)H-Index: 1
Last. Jan Krzek (Jagiellonian University Medical College)H-Index: 17
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β-carotene as a dietary supplement is a matter of interest to anyone who seeks to improve their skin condition or sight. Due to its antioxidative properties, carotenoids are involved in the prevention of severe conditions, such as cancer, heart disease, macular degeneration, or cataract, which makes them an object of scientific study. Thanks to its color, s-carotene is used as a food colorant, improving the appearance of foodstuff. A presented method was established for the identification and qu...
6 CitationsSource
#1Urszula Hubicka (Jagiellonian University Medical College)H-Index: 9
#2Barbara Żuromska-Witek (Jagiellonian University Medical College)H-Index: 4
Last. Jan Krzek (Jagiellonian University Medical College)H-Index: 17
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The lipophilicity of fifteen fluoroquinolones has been investigated. Reversed-phase thin layer chromatography with densitometric detection was applied to determine the RM0 factor. The RP-TLC investigations were performed in mixtures of organic modifier–water. The partition coefficients of examined fluoroquinolones were also calculated with computational programs. All the obtained data, from experimental methods and theoretical calculations, were compared and a suitable conclusion was reached. Th...
8 CitationsSource