Search results for: Andrzej Pokrywka

Items from 1 to 12 out of 12 results

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Comparison of GC–MS and MEKC methods for caffeine determination in preworkout supplements

Emilia Waraksa, Andrzej Pokrywka, Marek Konop, Jacek Namieśnik, more

In this study, GC–MS‐ and MEKC‐based methods for determination of caffeine (CAF) in preworkout supplements were developed and validated. The proposed protocols utilized minimal sample preparation (simple dilution and syringe filtration). The developed methods achieved satisfactory validation parameters, i.e. good linearity (R² > 0.9988 and R² > 0.9985 for GC–MS‐ and MEKC‐based method, respectively),...

article

Herbal medicine for sports: a review

Maha Sellami, Olfa Slimeni, Andrzej Pokrywka, Goran Kuvačić, more

Journal of the International Society of Sports Nutrition > 2018 > 15 > 1 > 1-14

The use of herbal medicinal products and supplements has increased during last decades. At present, some herbs are used to enhance muscle strength and body mass. Emergent evidence suggests that the health benefits from plants are attributed to their bioactive compounds such as Polyphenols, Terpenoids, and Alkaloids which have several physiological effects on the human body. At times, manufacturers...

article

Analytical approach for the determination of steroid profile of humans by gas chromatography isotope ratio mass spectrometry aimed at distinguishing between endogenous and exogenous steroids

Ewa Bulska, Damian Gorczyca, Izabela Zalewska, Andrzej Pokrywka, more

Journal of Pharmaceutical and Biomedical Analysis > 2015 > 106 > Complete > 159-166

The contamination of commonly used supplements by unknown steroids as well as their metabolites (parent compounds) become a challenge for the analytical laboratories. Although the determination of steroids profile is not trivial because of the complex matrix and low concentration of single compound, one of the most difficult current problem is to distinguish, during analytical procedure, endogenous...

article

Analytical procedure for steroid profiling valid for Athlete Biological Passport

Anna Jarek, Katarzyna Kowalczyk, Piotr Chołbiński, Katarzyna Chajewska, more

Chemical Papers > 2015 > 69 > 2 > 254-261

Although various attempts have been made to eliminate doping in sport, hitherto they all have proved futile. Moreover, the main class of substances that jeopardises the fair play rule remains the same — anabolic androgenic steroids (AAS). To date, longitudinal monitoring of the fluctuations of the endogenous steroids content for a given athlete is regardeded as the most effective approach to the detection...

article

RIGHT VENTRICLE LONGITUDINAL 2-D STRAIN REDUCTION AS A RESULT OF INTENSIVE TRAINING IN THE GROUP OF YOUNG, HIGH ENDURANCE ATHLETES

Marcin Konopka, Wojciech Krol, Andrzej Klusiewicz, Krystyna Burkhard, more

Journal of the American College of Cardiology > 2014 > 63 > 12(S) > A1647

article

Insights into Supplements with Tribulus Terrestris used by Athletes

Andrzej Pokrywka, Zbigniew Obmiński, Jadwiga Malczewska-Lenczowska, Zbigniew Fijatek, more

Journal of Human Kinetics > 2014 > 41 > 1 > 99-105

Herbal and nutritional supplements are more and more popular in the western population. One of them is an extract of an exotic plant, named Tribulus terrestris (TT). TT is a component of several supplements that are available over-the-counter and widely recommended, generally as enhancers of human vitality. TT is touted as a testosterone booster and remedy for impaired erectile function; therefore,...

article

Insights into Supplements with Tribulus Terrestris used by Athletes

Andrzej Pokrywka, Zbigniew Obmiński, Jadwiga Malczewska-Lenczowska, Zbigniew Fijatek, more

Journal of Human Kinetics > 2014 > 41 > 1 > 99-105

article

Relationship between ACTN3 R577X polymorphism and maximal power output in elite Polish athletes

Joanna Orysiak, Krzysztof Busko, Radoslaw Michalski, Joanna Mazur-Różycka, more

Medicina > 2014 > 50 > 5 > 303-308

The main purpose of this study was to examine the association between ACTN3 R577X polymorphism and the ability to produce peak power in young male athletes from various sports. Our hypothesis was that the ACTN3 R577X polymorphism is associated with jumping performance and athletes with RR genotype have better scores in tests than athletes with XX or RX genotype independently of the sport discipline...

article

Detection of β-methylphenethylamine, a novel doping substance, by means of UPLC/MS/MS

Piotr Chołbiński, Mariola Wicka, Katarzyna Kowalczyk, Anna Jarek, more

Analytical and Bioanalytical Chemistry > 2014 > 406 > 15 > 3681-3688

Novel substances of expected doping activity are constantly introduced to the market. β-Methylphenethylamine (BMPEA) is classified as a doping agent by the World Anti-Doping Agency as it is a positional isomer of amphetamine. In this work, the development and application of a simple and rapid analytical procedure that enables discrimination between both isomers is described. The analytes of interest...

article

Wykrywanie substancji psychotropowych we krwi metodą LC/MS/MS

Mariola Wicka, Piotr Chołbiński, Dorota Kwiatkowska, Andrzej Pokrywka

Problemy Kryminalistyki > 2014 > 284

Z roku na rok obserwuje się wzrost zjawiska zażywania środków uzależniających. Prowadzi to do pojawiania się problemu związanego z uzależnieniem jak również zażywanie środków psychoaktywnych stwarza duże zagrożenie dla uczestników ruchu drogowego. Rozporządzenie Ministra Zdrowia w sprawie środków działających podobnie do alkoholu oraz warunków i sposobu przeprowadzenia badań na ich obecność w organizmie...

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Determination of growth hormone releasing peptides (GHRP) and their major metabolites in human urine for doping controls by means of liquid chromatography mass spectrometry

Andreas Thomas, Sebastian Höppner, Hans Geyer, Wilhelm Schänzer, more

Analytical and Bioanalytical Chemistry > 2011 > 401 > 2 > 507-516

A family of small peptides has reached the focus of doping controls representing a comparably new strategy for cheating sportsmen. These growth hormone releasing peptides (GHRP) are orally active and induce an increased production of endogenous growth hormone (GH). While the established test for exogenous GH fails, the misuse of these prohibited substances remains unrecognized. The present study provides...

article

Screening for benfluorex and its major urinary metabolites in routine doping controls

Mario Thevis, Gerd Sigmund, Vassilios Gougoulidis, Simon Beuck, more

Analytical and Bioanalytical Chemistry > 2011 > 401 > 2 > 543-551

Benfluorex [1-(m-trifluoromethylphenyl)-2-(β-benzoyloxyethyl)aminopropane] has been widely used for the treatment of atherogenic metabolic disorders and impaired carbohydrate metabolism (particularly in obese type-II diabetic patients) as well as an anorectic drug. Due to its potentially performance-enhancing properties, benfluorex has been added to the list of prohibited compounds and methods of...

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