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Search results for: gas chromatography
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Prediction of Overall In Vitro Microsomal Stability of Drug Candidates Based on Molecular Modeling and Support Vector Machines. Case Study of Novel Arylpiperazines Derivatives
PublicationOther than efficacy of interaction with the molecular target, metabolic stability is the primary factor responsible for the failure or success of a compound in the drug development pipeline. The ideal drug candidate should be stable enough to reach its therapeutic site of action. Despite many recent excellent achievements in the field of computational methods supporting drug metabolism studies, a well-recognized procedure to model...
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Mass spectrometry based identification of geometric isomers during metabolic stability study of a new cytotoxic sulfonamide derivatives supported by quantitative structure-retention relationships
PublicationA set of 15 new sulphonamide derivatives, presenting antitumor activity have been subjected to a metabolic stability study. The results showed that besides products of biotransformation, some additional peaks occurred in chromatograms. Tandem mass spectrometry revealed the same mass and fragmentation pathway, suggesting that geometric isomerization occurred. Thus, to support this hypothesis, quantitative structure-retention relationships...
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Determination of nine high-intensity sweeteners in various foods by high-performance liquid chromatography with mass spectrometric detection
PublicationAn analytical procedure involving solid-phase extraction (SPE) and high-performance liquid chromatography-mass spectrometry has been developed for the determination of nine high-intensity sweeteners authorised in the EU; acesulfame-K (ACS-K), aspartame (ASP), alitame (ALI), cyclamate (CYC), dulcin (DUL), neohesperidin dihydrochalcone (NHDC), neotame (NEO), saccharin (SAC) and sucralose (SCL) in a variety of food samples (i.e. beverages,...
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Determination of the Major By-Products of Citrus hystrix Peel and Their Characteristics in the Context of Utilization in the Industry
PublicationKaffir lime (Citrus hystrix) is a popular citrus in Southeast Asia. Despite the growing interest in the peel of the fruit, the leaves are the most frequently used part of the fruit. The aim of the study was to determine the main by-products of the peel, such as pectins, minerals, essential oil, and bioactive compounds, and to evaluate the possibility of using them in various branches of industry. In the study of the essential oil...
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Rapid and simple multi-analyte LC–MS/MS method for the determination of benzodiazepines and Z-hypnotic drugs in blood samples: Development, validation and application based on three years of toxicological analyses
PublicationBenzodiazepines (BZDs) and Z-drugs have been particularly important treatments for sleeping and anxiety disorders for many years. However, recently, a number of new benzodiazepines (named designer benzodiazepines, DBZDs) were synthesised, but some of them have never been used in the clinic; they reached the black drug market as new psychoactive substances and are used for recreational purposes. The abuse of these substances has...
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Seasonal changes of mercury speciation in the coastal sediments
PublicationPurpose Mercury speciation in sediments is linked to environmental conditions and processes. Domination of particular mercury species depends on its source, displays considerable seasonal behavior, and may be further modified due to oxygen levels, icing conditions, or the input of fresh organic matter. The purpose of this study was to examine the coastal area of the Gulf of Gdańsk in terms of mercury contamination and the influence...
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The Action Mechanisms, Anti-Cancer and Antibiotic-Modulation Potential of Vaccinium myrtillus L. Extract
PublicationHerbal medicinal products containing Vaccinium myrtillus L. (bilberry) fruits and fruit extracts are widely available in the market. Although bilberry leaves and stems are considered as bio-waste, they contain much higher levels of phenolic compounds than fruits. The study aimed to investigate the antimicrobial and anticancer potential of aerial part extracts from Vaccinium myrtillus L. (V. myrtillus, VM) plants harvested at high...
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Application of gas chromatographic data and 2D molecular descriptors for accurate global mobility potential prediction
PublicationMobility is a key feature affecting the environmental fate, which is of particular importance in the case of persistent organic pollutants (POPs) and emerging pollutants (EPs). In this study, the global mobility classification artificial neural networks-based models employing GC retention times (RT) and 2D molecular descriptors were constructed and validated. The high usability of RT was confirmed based on the feature selection...
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SPME as a method of sample preparation for GC analysis of VFAs
PublicationW niniejszym artykule omówiono szczegółowo technikę mikroekstrakcji do fazy stacjonarnej, stosowaną na etapie przygotowania próbek, w celu oznaczania lotnych kwasów tłuszczowych.
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Determination of Volatile Organic Compounds in Indoor Air in the Gdansk Area Using Permeation Passive Samplers
PublicationPassive dosimetry — known for over a hundred years — is still a useful tool in monitoring air pollutants. In this work, permeation passive samplers were used to determine indoor air quality in 22 apartments located in the Gdansk area in the northern part of Poland. The results obtained by the passive sampling technique were compared to those obtained by dynamic sampling. Attempts were also made to identify indoor sources of...
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Determination of SCFAs in water using GC-FID. Selection of the separation system
PublicationIn the present study, an analytical procedure was developed for the determination of short-chain fatty acids (SCFAs) in landfill leachate and municipal wastewater employing injection of aqueous samples to gas chromatograph with flame ionization detector (GC-FID). Chromatographic conditions such as a separation system, injection volume, oven temperature program were investigated and selected. With two columns, one with a polar (polyethylene...
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PBDEs in environmental samples: Sampling and analysis
PublicationThe paper reviews the subject literature concerning analytical procedures routinely sed for monitoring polybrominated diphenyl ethers (PBDE) in environmental samples. It describes and summarizes subsequent stages of analytical procedure including sample collection and preparation, extraction, clean-up and final determination. Different approaches with their advantages and limitations are presented. Special attention is drawn to...
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House dust as a source of analytical information on concentration of polybrominated diphenyl ethers (PBDEs) - first approach
PublicationPolybrominated diphenyl ethers (PBDEs), which are best recognized as flame retardants, were in 2001, by virtue of Stockholm Convention, listed in a group of Persistent Organic Compounds (POPs). Increasing concentration levels of PBDEs, reported in human tissues (e.g., blood, serum, breast milk, etc.) haverecently caught worldwide concern due to their potential tendency to disrupt thyroid hormones, neurobehavioral deficits and endocrine...
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The analysis of raw spirits – a review of methodology
PublicationAgricultural distillates (raw spirits) are alc oholic l iquids obtained thro ugh dis till ation (preceded by alcoholic ferm entation)of specific agricultural products that do not have the properties of ethyl alcohol or a spirit, but still retain th e aroma andtaste of the raw ingredients used. This review is a brief overview of agricultural distillates and of some methods commonlyused (GC-MS, GC-FID, GC-O, electronic nose) for...
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Development of SPME fiber coatings with tunable porosity for physical confinement of ionic liquids as an extraction media
PublicationExtending the use of ionic liquids in sample preparation techniques remains a challenge. This paper presents procedures enabling the easy application of ionic liquids to the SPME technique. For this purpose, two approaches for producing a porous silica coating on a metal rod were investigated. Two silica precursor and porogen systems were used in the research: K2SiO3 + Formamide and Tetramethyl-orthosilicate + Polyethylene oxide....
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Miniaturized, green salting-out liquid–liquid microextraction coupled with GC–MS used to evaluate biogenic amines in wine samples
PublicationMonitoring of the biogenic amines (BAs) content in food products, including wine, is important due to the health and safety of consumers and from the quality control point of view. In a given study, simultaneous derivatization and salting-out liquid–liquid microextraction (SALLME) coupled with GC–MS for BAs determination from wine samples was developed. For the optimization the Box-Behnken design was applied, where three independent...
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A comparative study of organic pollutants in seawater, sediments and oyster tissues at Hab River Delta, Balochistan coast, Pakistan
PublicationThis chapter is about a Comparative Study of Organic Pollutants in Seawater, Sediments, and Oyster Tissues at Hab River Delta, Balochistan Coast, Pakistan.
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Detection, identification and determination of resveratrol in wine. Problems and challenges
PublicationResveratrol is a compound synthesized by plants in response to unfavorable conditions of growth like mechanical injury, siege of bacteria or fungi and UV exposure. It is concentrated mostly in grapes skin and further more in the products made from grapes especially red wines. Each wine is characterized by different amount of given stilbene since its occurrence is affected by many factors like: types of grapes, environment (climate,...
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Determination of polybrominated diphenyl ethers (PBDEs) in dust samples collected in air conditioning filters of different usage – method development
PublicationThis study presents the results of studies aimed at the development of an analytical procedure for separation, identification, and determination of PBDEs compounds in dust samples collected from automotive cabin air filters and samples collected from filters installed as part of the air purification system in academic facilities. Ultrasound-assisted dispersive solid phase extraction (UA-dSPE) was found to perform better in terms...
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Application potential of dummy molecularly imprinted polymers as solidphase extraction sorbents for determination of low-mass polybrominated diphenyl ethers in soil and sediment samples
PublicationDespite the introduction of restrictive regulations in the USA and the European Union, polybrominated diphenyl ethers (PBDEs) are still found in various types of environmental and biological samples at significant concentration levels. The presence of these persistent organic pollutants in the environment raises important issues because of their negative impact on immunological and neurological systems, and on the hormonal balances...
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Analytical and legislative challenges of sewage sludge processing and management
PublicationThis article presents the most popular methods of sewage sludge management and analytical techniques which could be a powerful tool in designing new sewage sludge management methods. Chemical analysis is also described as a vital point at the subsequent stages of technological processes control and sewage sludge quality assessment. It is also an instrument essential to maintaining control of processed sewage sludge introduced to...