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Open access

Anna Gajda and Andrzej Posyniak

Abstract

A liquid chromatography – tandem mass spectrometry (LC-MS/MS) method for the determination of oxytetracycline (OTC), 4-epi oxytetracycline (4-epi OTC), tetracycline (TC), 4-epi tetracycline (4-epi TC), chlortetracycline (CTC), 4-epi chlortetracycline (4-epi CTC), doxycycline (DC), minocycline (MINO), methacycline (META) and rolitetracycline (ROLI) residues in muscles was developed. The procedure consisted of an oxalic acid extraction followed by protein removal with trichloroacetic acid. Further solid phase clean-up on polymeric (Strata X) reversed phase columns was performed to obtain an extract suitable for LC-MS/MS analysis. The tetracyclines were separated on a C 18 analytical column with mobile phase consisting of 0.01% formic acid in acetonitrile and 0.01% formic acid in water in gradient mode. The method was validated according to the Commission Decision 2002/657/EC. The recoveries of all target compounds were 91.8% – 103.6%. The decision limits were from 109.0 to 119.8 μg/kg and detection capability varied within the range of 122.2 to 137.6 μg/kg, depending on the analyte.

Open access

Anna Gajda, Andrzej Posyniak and Tomasz Błądek

Abstract

For the measurement of tulathromycin distribution in swine plasma an accurate and reliable analytical method was developed. The extraction was performed with oxalic acid buffer (pH=4.0). Plasma samples were cleaned up by solid phase extraction procedure using polymeric cartriges. Chromatographic separation was achieved on a C 18 analytical column using mobile phase consisting of acetonitrile, 0.1% formic acid in gradient mode. Detection was carried out by liquid chromatography tandem mass spectrometry. Azithromycin was used as internal standard. The method has been successfully validated. The recovery from spiked samples ranged from 94% to 110%. The limit of detection was 2 ng/mL and the limit of quantification was 5 ng/mL. The method was developed to investigate the pharmacokinetics of tulathromycin in swine plasma. Applicability of the method was tested with plasma from swine administered with a single dose of tulathromycin.

Open access

Anna M. Gajda, Ewa A. Czyż and Anthony R. Dexter

Abstract

The aim of this study was to compare the effects of different farming systems (organic, integrated, conventional and monoculture) on some soil properties as: bulk density, contents of readily-dispersible clay, organic matter and particulate organic matter, and enzymatic activity measured in terms of the intensity of fluorescein diacetate hydrolysis. Soil under permanent grass was used as a control. The study was conducted on the 20 years lasting field experiment. Samples of Haplic Luvisol soil were collected twice a year on fields under winter wheat from the layers of 0-5, 5-10, 15-20, and 30-35 cm. Within arable soils the soil under organic farming contained the greatest amount of organic matter, which influenced strongly the readily-dispersible clay content, especially in the layer of 5-20 cm. The readily-dispersible clay content in soil under organic farming was 3 times lower, as compared to the conventional and monoculture farming. The highest contents of particulate organic matter 6.2 and 3.5 mg g−1 air dry soil, on average were measured in the 0-5 cm layer of control soil and soil under organic farming, respectively. Also, soil under organic farming and control soil from the depth of 0-5 cm showed 2-2.5 times greater activity of microorganisms in fluorescein diacetate hydrolysis than soil under conventional and monoculture farming. Increase of concentration of organic matter in soil under organic farming decreased soil bulk density. Statistical analysis showed significant correlations between studied parameters of soil quality and confirmed their effectiveness as indicators of disturbances in soil environment.

Open access

Anna Gajda, Andrzej Posyniak and Grzegorz Tomczyk

Abstract

For the purpose of quantitative determination of doxycycline (DC) residues in tissues, a sensitive liquid chromatography - tandem mass spectrometry (LC-MS/MS) method was developed. The method was used to determine DC residues in chicken tissues (breast and thigh muscle, liver and kidney) after oral administration with drinking water to five-weak-old broiler chickens. The DC was administered for five consecutive days at a therapeutic dose of 10 mg/kg b.w. once a day. The tissues were collected after 6 h, 24 h, 7 d, and 8 d. The method was validated and the decision limit was established for muscle - 109.2 μg/kg, for liver - 326.1 μg/kg, and for kidney - 634.0 μg/kg. The detection limit was 2 μg/kg and the limit of quantification was 5 μg/kg. In a short period after ceasing the treatment, the detected concentrations of DC were much higher than the established maximum residue limit values. The highest residue concentrations of DC were observed in the kidney, followed by the liver and muscle. The lowest concentration of DC was determined in tight muscle.

Open access

Anna Gajda, Andrzej Posyniak, Andrzej Bober, Tomasz Błądek and Jan Żmudzki

Summary

A liquid chromatography method with UV detection for determination of oxytetracycline (OTC) in honey has been developed. The samples were extracted with the solution of oxalic acid. The clean-up procedure was performed by solid phase extraction (SPE) using polymeric Strata X and carboxylic acid cartridges. Chromatographic separation was carried out on the Luna C8 analytical column with mobile phase consisting of acetonitrile-0.02 M oxalic acid. The method has been successfully validated according to the requirements of the European Decision 2002/657/EC and this method is used in routine control of oxytetracycline in honey samples. The limit of detection (LOD) and limit of quantification (LOQ) of the presented method were 10 and 12.5 μg/kg, respectively. The developed method has also been verified in quantitative determination of oxytetracycline residues in honey after experimental treatment with this product in bee colonies.

Open access

Grażyna Topolska, Anna Gajda and Urszula Imińska

Summary

Estimations of honeybee colony winter losses in Poland have been carried out at Warsaw University of Life Sciences since 2008 (in 2008 they concerned the two winters of 2006/07 and 2007/08), using a preliminary questionnaire in 2008 and the standardized COLOSS questionnaire since 2009. During the first years of the survey, concerning the period of autumn 2006 - spring 2012, the multimode method of data collection was used, and beekeepers sent in between 393 and 769 questionnaires a year. Overall, the number of participants increased, but in particular voivodeships it fluctuated. The estimated overall winter colony loss in Poland was low during the winter of 2006/07 (10%) and quite low during the winter of 2008/09 (11.5%). In other years it was substantially higher reaching 15.2% in 2007/08, 14.8% 2009/10, as much as 18.3% in 2010/11 and then down to 15.8% in 2011/12. A similar pattern of average losses was observed, but each year, excluding the winter of 2010/11, at least 50% of beekeepers reported acceptable losses of only up to 10%. During the analysis of the spatial pattern of overall losses, some data which could blur the pattern were eliminated. The results suggest that such climatic factors as a warm autumn but also high summer precipitation, followed by low winter temperatures influenced the spatial distribution of the losses.

Open access

Kamila Skwierawska, Anna Waszczuk-Gajda, Agnieszka Perkowska-Ptasińska, Grzegorz Basak and Wiesław W. Jędrzejczak

Abstract

Termin gammapatia monoklonalna o znaczeniu nerkowym (MGRS) w akronimie różni się jedynie jedną literą od gammapatii monoklonalnej o nieokreślonym znaczeniu (MGUS), jednakże w znaczeniu klinicznym jest to zupełnie inna jednostka. W przebiegu MGRS białko produkowane przez klon komórek uszkadza nerki, przez co może prowadzić do ich niewydolności. W niniejszym artykule dokonano przeglądu piśmiennictwa dotyczącego jednostek chorobowych zaliczanych do grupy MGRS, ich podziału ze względu na typ uszkodzenia nerek i charakterystykę deponowanych w nich złogów. W pracy omówiono także współczesne możliwości leczenia w poszczególnych jednostkach chorobowych zaliczanych do MGRS.

Open access

Anna M. Gajda, Ewa A. Czyż, Anthony R. Dexter, Karolina M. Furtak, Jarosław Grządziel and Jadwiga Stanek-Tarkowska

Abstract

The effects of different tillage systems on the properties and microbial diversity of an agricultural soil was investigated. In doing so, soil physical, chemical and biological properties were analysed in 2013-2015, on a long-term field experiment on a loamy sand at the IUNG-PIB Experimental Station in Grabów, Poland. Winter wheat was grown under two tillage treatments: conventional tillage using a mouldboard plough and traditional soil tillage equipment, and reduced tillage based on soil crushing-loosening equipment and a rigid-tine cultivator. Chopped wheat straw was used as a mulch on both treatments. Reduced tillage resulted in increased water content throughout the whole soil profile, in comparison with conventional tillage. Under reduced tillage, the content of readily dispersible clay was also reduced, and, therefore, soil stability was increased in the toplayers, compared with conventional tillage. In addition, the beneficial effects of reduced tillage were reflected in higher soil microbial activity as measured with dehydrogenases and hydrolysis of fluorescein diacetate, compared with conventional tillage. Moreover, the polimerase chain reaction – denaturing gradient gel electrophoresis analysis showed that soil under reduced till-age had greater diversity of microbial communities, compared with conventionally-tilled soil. Finally, reduced tillage increased organic matter content, stability in water and microbial diversity in the top layer of the soil.

Open access

Małgorzata Gbylik-Sikorska, Andrzej Posyniak, Anna Gajda and Tomasz Błądek

Abstract

The study presents a method for determination of enrofloxacin and ciprofloxacin in albumin and freeze-dried-eggs with the use of liquid chromatography with fluorescence detection. The procedure enables a simple isolation of fluoroquinolones from albumin based on extraction with acetonitrile, and from freeze-dried-eggs with acetonitrile under alkaline conditions. The samples have been analysed on ultracarb C8 liquid chromatography column. The gradient elution programmes consisted of the mixture of 0.03 M phosphoric acid with 0.002 M sodium 1-heptanesulfonate monohydrate and acetonitrile. The method has been validated according to requirements of the European Decision 2002/657/EC. Recoveries ranged from 78% to 83% for spiked freeze-dried-eggs and from 89% to 91% for albumin. The developed method can be applied for determination and confirmation of enrofloxacin and ciprofloxacin in albumin and freeze-dried-eggs.

Open access

Tomasz Błądek, Andrzej Posyniak, Anna Gajda, Małgorzata Gbylik and Jan Żmudzki

Abstract

A liquid chromatographic method coupled with tandem mass spectrometry for determination of residues of β-lactams, macrolides, tetracyclines, quinolones, sulfonamides, and lincosamides in eggs has been described. Analytes were isolated from egg samples by solvent extraction method and extracts were cleaned by filtration on OASIS HLB cartridges. The whole procedure was validated according to European Commission Decision 2002/657/EC. The recovery ranged between 86% and 110%. The repeatability was below 16% and within-laboratory reproducibility was lower than 20%. The method was successfully applied in the official control of antibacterial compounds residue in Poland.