Piotr Stepnowski | University of Gdansk (original) (raw)

Papers by Piotr Stepnowski

Environ Sci Pollut Res, 2002

... molecular weight is extensive (from several to more than thousands of kDa) and is thus divide... more ... molecular weight is extensive (from several to more than thousands of kDa) and is thus divided into three categories: low-molecular-weight chitosan (LMWC), medium-molecular-weight chitosan (MMWC) and high-molecular-weight chitosan (HMWC) (Harish Prashanth & ...

Carbohydrate Research, 2008

Analytical Sciences the International Journal of the Japan Society For Analytical Chemistry, Oct 10, 2008

The usefulness of ion-pair reagents in selective solid reversed-phase extraction of one N-butyl-4... more The usefulness of ion-pair reagents in selective solid reversed-phase extraction of one N-butyl-4-methylpyridinium and four short-chain alkylimidazolium ionic liquid cations from aqueous media was investigated using various concentrations of alkylsulfonates with different alkyl chain lengths. Final recoveries of the two cations with the shortest alkyl residues were poorer than those of the other, more hydrophobic compounds. Moreover, the recovery values were little affected by the different concentrations of the reagents. In nearly all cases, the best recoveries were obtained with the 1-heptanesulfonate reagent. The analytical performance parameters included excellent linearity over four orders of magnitude, with limits of detection ranging from 0.01 to 0.06 ppm, and very good precision and accuracy. The method was successfully used to extract ionic liquids from spiked seawater and freshwater samples. Recoveries and limits of detection were quite similar to those obtained with preconcentrated standard solutions.

Carbohydrate Research, Feb 1, 2009

... Ulrika Olsson a , Andrej Weintraub b and Göran Widmalm a , Corresponding Author Contact Infor... more ... Ulrika Olsson a , Andrej Weintraub b and Göran Widmalm a , Corresponding Author Contact Information , E-mail The Corresponding Author. ... Received 22 November 2007; revised 3 January 2008; accepted 7 January 2008. Available online 15 January 2008. Abstract. ...

Journal of Pharmaceutical and Biomedical Analysis, Sep 1, 2010

Environ Toxicol Pharmacol, 2005

The usefulness of in vitro AMP deaminase inhibition was examined as a potential molecular method ... more The usefulness of in vitro AMP deaminase inhibition was examined as a potential molecular method in risk assessment of xenobiotics. The enzyme participates in the principal purine nucleotide interconversion and degradation pathways, and its absence caused perturbations in the cellular ATP pool. The compounds selected were synthetic musks with a known negative environmental impact and the toxicologically unknown ionic liquids and N-glucopyranosyl ammonium bromides, which have recently attracted much interest from the chemical and related industries. All the compounds tested demonstrated a dose-dependent inhibition of AMP deaminase activity. IC(50) ranged from 0.3μM for polycyclic musks to 500μM for N-glucopyranosyl trimethylammonium bromide. Analysis of Dixon plots showed the inhibition type for all the compounds to be noncompetitive. The results support the choice of such an assay for the prospective risk assessment of these compounds.

Journal of Soils and Sediments, Feb 18, 2009

Anaesthesiology Intensive Therapy, 2012

J Environ Radioact, 2000

The paper presents the results of 210Po determinations, and 210Po/210Pb activity ratios, in the t... more The paper presents the results of 210Po determinations, and 210Po/210Pb activity ratios, in the tissues and organs of the Baltic crustacean Saduria entomon. Additionally, the subcellular localisation of 210Po in the hepatopancreas of this organism has been studied using centrifugation followed by determination of the 210Po concentrations in isolated fractions. The 210Po concentrations fall within the range 0.63–543.5Bq kg−1 (dry

The Science of the total environment, Jan 9, 2015

Anticancer drugs (ACDs) exhibit high biological activity, they are cytotoxic, genotoxic, and are ... more Anticancer drugs (ACDs) exhibit high biological activity, they are cytotoxic, genotoxic, and are constantly released into the environment as a result of incomplete metabolism. Consequently they pose a serious threat to the environment and human health due to their carcinogenic, mutagenic and/or reproductive toxicity properties. Knowledge of their bioavailability, including their sorption to soils and their impact on the soil-groundwater pathway, is crucial for their risk assessment. Laboratory batch and column leaching tests are important tools for determining the release potential of contaminants from soil or waste material. Batch and column tests were carried out with soils differing in physicochemical properties, each spiked with cyclophosphamide (CK) or ifosfamide (IF). Moreover, due to the fact that environmental pollutants may occur as coexisting compounds in the soil the mobility evaluation for ACDs in the mixture with metoprolol (MET; β-blocker) as a co-contaminant was perfo...

Przemysl Chemiczny

The paper presents the state of knowledge on the chromatographic techniques used in the analysis ... more The paper presents the state of knowledge on the chromatographic techniques used in the analysis of insect lipids. Lipids are one of the forms of protection against entomopathogenic fungi. Their composition may include a number of different compounds, such as long chain hydrocarbons, waxes, alcohols, aldehydes and free fatty acids. These compounds may be presented in different amounts depending on the species of insects, living environment, lifestyle, seasons, etc. The most commonly used techniques in the analysis of lipids of insects are: gas chromatography, high performance liquid chromatography, and combined techniques such as gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS). Compounds present in the cuticular lipids of insects may serve diverse functions such as minimizing transpiration. It was also found that extracts of insects possess antifungal effects. Determination of lipid profiles and biological activity of the identified compounds can effectively contribute to the knowledge of the defense mechanisms of insects, and thus, impact the development of new methods of combating harmful insects.

Current Organic Chemistry

ABSTRACT

The Science of the total environment, Jan 15, 2015

The presence of pharmaceuticals in drinking water, even at very low concentrations, has raised co... more The presence of pharmaceuticals in drinking water, even at very low concentrations, has raised concerns among stakeholders such as drinking-water regulators, governments, water suppliers and the public, with regard to the potential risks to humans. Despite this, the occurrence and the fate of pharmaceuticals in drinking waters of many countries (e.g. in Poland) remains unknown. There is a lack of sufficiently sensitive and reliable analytical methods for such analyses and a need for more in-depth hydrogeological analysis of the possible sources of drug residues in drinking water. In this paper, a multi-residual method for the simultaneous determination of seventeen human pharmaceuticals in drinking waters has been developed. Large-volume extractions using Speedisk extraction disks, and derivatization prior to GC-MS-SIM analysis using a new silylating agent DIMETRIS were applied. The method detection limits (MDLs) ranged from 0.9 to 5.7ng/L and the absolute recoveries of the target c...

Biochemical Systematics and Ecology, 2015

Gas Chromatography in Plant Science, Wine Technology, Toxicology and Some Specific Applications, 2012

Journal of Chemistry, 2015

Even though the methodology used for the determination ofβ-blockers andβ-agonists in environmenta... more Even though the methodology used for the determination ofβ-blockers andβ-agonists in environmental samples is based mainly on solid-phase extraction (SPE) and gas chromatography or liquid chromatography with mass spectrometric detection, the available literature data on the applied SPE procedures is rather sparse. In this paper such comparison is presented. Moreover, the usefulness of the eight SPE cartridges for the determination of fiveβ-blockers (acebutolol, atenolol, metoprolol, nadolol, and propranolol) and twoβ-agonists (salbutamol and terbutaline) in environmental aqueous samples using GC techniques is tested. Among them, three (the trifunction sorbent Strata Screen C, the copolymers LiChrolut EN, and the functionalized copolymer Isolute ENV+) were used for the first time for this purpose. It was confirmed that polystyrene-divinylbenzene-N-vinylpyrrolidone copolymers (PS-DVB-VP, Strata-X, and Oasis HLB cartridges) have a better potential than a cation-exchange sorbent for the...

Journal of food and nutrition research

The glycoalkaloid, sterol and fatty acid contents were determined in raw and blanched leaves of t... more The glycoalkaloid, sterol and fatty acid contents were determined in raw and blanched leaves of the gboma eggplant (Solanum macrocarpon L.). The results of the study revealed that 5 min blanching was sufficient to obtain a 35–56% decrease in the glycoalkaloid content in leaves to values below 200 mg·kg-1 of fresh weight, which is regarded as a safe level in foods. Processing also significantly decreased the free fatty acid content and increased the free sterol content. In raw and blanched leaves, however, the contents of total fatty acids and sterols were comparable. The total sterol content in S. macrocarpon leaves was as high as 3.2–4.0 g·kg-1 of dry weight, while the total fatty acid content was 23.0–32.1 g·kg-1 of dry weight. The cholesterol contribution to total sterols did not exceed 10%. While saturated compounds were most abundant in the free fatty acid fraction, total fatty acids were dominated by C18 polyunsaturated compounds. Additionally, isomerization of unsaturated fat...

Environmental science and pollution research international, Jan 19, 2015

Although sulfonamides (SAs) are among the most commonly used veterinary drugs and their presence ... more Although sulfonamides (SAs) are among the most commonly used veterinary drugs and their presence in the environment is well documented, knowledge of their fate and behavior in the soil environment is still limited, especially for sulfisoxazole (SSX) which is characterized by the lowest (among other SAs) pK a value associated with acid-base equilibrium of sulfonamide group. Thus, this work was focused on determining the sorption potential of SSX onto natural soils differing in physicochemical properties. All the results were modeled using linear, Freundlich, Langmuir, Dubinin-Radushkevich, and Temkin sorption isotherms. The established sorption coefficients (K d ) for SSX were quite low (from 0.27 to 0.95 L kg(-1)), which indicated that this substance is highly mobile and has the potential to run off into surface waters and/or infiltrate ground water. The sorption data of SSX is well fitted to the Freundlich isotherm model (R (2) > 0.968). Moreover, we assessed the sorption mechan...