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Search results for: ELUTION
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Solid phase extraction and sequential elution for pre-concentration of traces of Mn and Zn in analysis of honey by flame atomic absorption spectrometry
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Progressing Pollutant Elution from Snowpack and Evolution of its Physicochemical Properties During Melting Period— a Case Study From the Sudetes, Poland
PublicationMain aim of the work assumed recognition of physicochemical changes in snowpack occurring during the melting period. Properties of snow cover had been identified at two sites in Western Sudetes mountains (860 and 1228 m asl) in SW Poland since the end of January, and monitored until the disappearance of snow in late Spring. Snow pit measurements and sample collection at both sites were made followed by chemical analyses with the...
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High-performance liquid chromatography thermodynamic study of new potential antiepileptic compounds on a cholesterol column using isocratic elution with methanol/water and acetonitrile/water eluent systems
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Interference-Free Determination of Trace Copper in Freshly Ripened Honeys by Flame Atomic Absorption Spectrometry Following a Preconcentration by Solid-Phase Extraction and a Two-Step Elution Process
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A research on the optimal conditions for separation and identyfication of the components from the Droseraceae extracts by column liquid chromatography
PublicationThe isolation of the components with anticipated biological properties i.e. antimicrobial, fungicidal, antioxidant and perhaps anticancer activity is for many years a one of the biggest issues of modern separation science. Their obtaining based on the isolation of the components with the biological activity from in vitro cultured plants by extraction techniques is often more difficult than their production by the chemical synthesis.The...
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Troubleshooting of the determination of bisphenol A at ultra-trace levels by liquid chromatography and tandem mass spectrometry
PublicationDetermination of trace amounts of bisphenol A (BPA) may cause problems mainly related to the presence of BPA in solvents (even in LC-MS grade), laboratory vessels, and plastic equipment used for sample preparation. Variable and sometimes significant amounts of BPA present in the background cause problems in obtaining good repeatability of measurements at the ultra-trace levels. Such observations (i.e., poor repeatability of results)...
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A new procedure for the determination of distillation temperature distribution of high-boiling petroleum products and fractions
PublicationThe distribution of distillation temperatures of liquid and semi-fluid products, including petroleum fractions and products, is an important process and practical parameter. It provides information on properties of crude oil and content of particular fractions, classified on the basis of their boiling points, as well as the optimum conditions of atmospheric or vacuum distillation. At present, the distribution of distillation temperatures...
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Sensitive simultaneous determination of 19 fluorobenzoic acids in saline waters by solid-phase extraction and liquid chromatography–tandem mass spectrometry
PublicationA solid-phase extraction (SPE) procedure using C18 stationary phase was optimized for the preconcentration of 19 fluorinated derivatives of benzoic acid (FBA): mono-, di-, tri-, and tetrafluorosubstituted in the ring, trifluoromethylbenzoic acid and 3,5-bistrifluoromethyl benzoic acid from undiluted salt-rich (>20%) reservoir waters. Quantitative (>90%) retention/elution of 16 out of 19 analyte compounds was achieved allowing a...
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Liquid chromatography techniques for separation of flavonoids from Droseraceae
PublicationFlavonoids which are presented in insectivorous plants of the Droseraceae family have wide range of advantageous properties i.e. an antioxidant, anti-inflammatory and antimicrobial activities, antitumor activity was reported as well.The purpose of the research was to develop the most favourable conditions for liquid chromatographic separation and identification of myricetin and quercetin in extracts of insectivorous plants. In...
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Hydrophobic and hydrophilic properties of pollutants as a factor influencing their redistribution during snowpack melt
PublicationGlaciers accumulate organic pollutants delivered by snow. However, our understanding of the exact dynamics of organic pollutants in the snowpack relies primarily on laboratory experiments and mathematical models. To fill the gap related to the detailed field data, we have conducted observations of melting snow profiles in two locations and three different stages of melting on one High Arctic glacier, as well as in superimposed...
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Determination of phenylbutazone, sulfamethazine, carbendazim and linuron using a novel pine bark biosorbent for solid-phase extraction (SPE) with high-performance liquid chromatography (HPLC)
PublicationThe paper presents a novel pine bark based biosorbent for solid-phase extraction (SPE). The morphology and composition of the pine bark were characterized using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The biosorbent was used for the preparation of wastewater for the determination of phenylbutazone, sulfamethazine, carbendazim, and linuron by high performance liquid chromatography with...
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Superimposed ice as nutrient storage
PublicationNutrient cycling in the glacial environment is known from the perspective of meltwater release and snowpack elution processes, but the superimposed ice temporary storage remains poorly understood. In this study, the enrichment of superimposed ice in nutrient ions: nitrite, nitrate and ammonium was studied in more detail. The release of these ions from superimposed ice into a supraglacial stream was considered also, additionally...
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Non-enzymatic glutathione-mediated conjugation of unsymmetrical bisacridine C-2028 with anticancer activity
Open Research DataThe presented data complement the studies on the interplay between C-2028 (anticancer-active unsymmetrical bisacridine) and the glutathione S-transferase/glutathione (GST/GSH) system.
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A method for a comprehensive lipidomic analysis of flaxseed (Linum usitatissimum) with the use of LC–Q-TOF-MS and dispersive micro-solid-phase (μDSPE) extraction
PublicationFlaxseed (FS) is one of the richest sources of α-linolenic acid oil and lignans, and it is suggested that the consumption of flaxseed may contribute to the prevention of certain chronic diseases such as many types of cancer, diabetes, cardiovascular diseases and cerebrovascular stroke. Here, we demonstrate a new method for comprehensive FS lipidome profiling with the use of LC–Q-TOF-MS and dispersive micro-solid-phase extraction....
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Assay of Cystathionine-γ-synthase (CaStr2p) activity determination.
Open Research DataThe study aimed to obtain conditions optimal for the activity of Candida albicans cystathionine-γ-synthase (CaStr2p) determination. The selection of appropriate reaction conditions included the identification of the reaction buffer and its pH, substrate, and enzyme concentrations. The activity of Str2p was measured by the detection of decrease of the...
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Activity assay of O-Acetyl-L-homoserine sulfhydrylase (CaMet15p).
Open Research DataThe study aimed to obtain conditions optimal for the activity of O-acetyl-L-homoserine sulfhydrylase (CaMet15p) and a method suitable for its measurement. The selection of appropriate reaction conditions included the identification of the reaction buffer and its pH, substrate and enzyme concentrations. The activity of CaMet15p was measured by the detection...
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Application of normal-phase high-performance liquid chromatography followed by gas chromatography for analytics of diesel fuel additives
PublicationThe paper presents the results of investigations on new procedures of determination of selected cleaning additives in diesel fuel. Two procedures: one-step analysis using gas chromatography with flame ionization detection (GC-FID) or mass spectrometry (GC-MS) and a two-step procedure in which normal-phase high-performance liquid chromatography (NP-HPLC) was used for preliminary separation of the additives, were compared. The additive...
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Research on the separation properties of empty-column gas chromatography (EC-GC) and conditions for simulated distillation (SIMDIS)
PublicationThe paper presents the results of investigations on new procedures of determination of selected cleaning additives in diesel fuel. Two procedures: one-step analysis using gas chromatography with flame ionization detection (GC-FID) or mass spectrometry (GC-MS) and a two-step procedure in which normal-phase high-performance liquid chromatography (NP-HPLC) was used for preliminary separation of the additives, were compared. The additive...
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Levels of 13 multi-class pesticide residues in Polish honeys determined by LC-ESI-MS/MS
PublicationLevels of 13 pesticides in 40 honey samples form Poland are reported. A rapid and sensitive method was developed for the LC-ESI-MS/MS determination of multi-class pesticide residues in honey samples. Liquid-liquid extraction (LLE) on a diatomaceous earth support (requiring the use of small amounts of organic solvent), followed by chromatographic separation on a C18 column and gradient elution were employed. The method quantifies...
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Techniki chromatografii w rozdzielaniu i oznaczaniu ekdysteroidów w Rhaponticum carthamoides
PublicationRhaponticum carthamoides to syberyjska endemiczna wieloletnia bylina, od wieków wykorzystywana w medycynie ludowej, jako preparat wzmacniający organizm. Główną grupą związków chemicznych, występujących w roślinie oraz wzbudzających szczególne zainteresowanie, ze względu na wykazywaną aktywność, są ekdysteroidy. Dlatego też poznanie ich dokładnego składu oraz stężeń w tkankach roślinnych staje się istotnym elementem poznawczym oraz...
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The role of centrifugal partition chromatography in the removal of β-asarone from Acorus calamus essential oil
PublicationΒ-asarone is a phenylpropane derivative present in the rhizomes of Acorus calamus, that was proved to exhibit toxic effects in humans. Because of its presence the whole plant that is commonly used in traditional medicine for its sedative, anti-inflammatory, neuroprotective and other properties has limited application nowadays. In the study, qualitative and quantitative analysis of a collection of nine essential oil (EO) samples...
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Sensitive determination of isoprostanes in exhaled breath condensate samples with use of liquid chromatography-tandem mass spectrometry
PublicationOxidative stress is the hallmark of various inflammatory lung diseases. Increased concentrations of reactive oxygen species in the lungs are reflected by elevated concentrations of oxidative stress markers in the breath, airways, lung tissue and blood. The aim of this work was to develop a method for the fast measurement of F2 isoprostanes in exhaled breath condensate (EBC) samples using equipment which is nowadays available and...
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Studies of the separation performance of silanized silica gel for simulated distillation
PublicationWe present the results of investigations of the chromatographic (sorptive) properties of silanized silica gel as a stationary phase for gas chromatography used for simulated distillation. Commercially available silanized sorbent (particle diameter range 63–200 m, average pore size 60 Å) was sieved to obtain the 80–100 mesh fraction (180–150 m). The obtained results revealed that silanized silica gel allows the complete separation...
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Determination of flavanols by liquid chromatography with fluorescence detection. Application to the characterization of cranberry-based pharmaceuticals through profiling and fingerprinting approaches
PublicationIn this work, a new method based on reversed-phase high-performance liquid chromatography (HPLC) with fluorescence detection (FLD) was established for the determination of catechins and related oligomeric proanthocyanidins (PACs) in cranberry-based pharmaceuticals. Compounds were recovered by liquid extraction using methanol/water/hydrochloric acid (60:39:1, v:v:v) as the extraction solvent. The chromatographic separation was carried...
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Stopniowa chromatografia cienkowarstwowa w normalnych układach faz (NP-TLC), jako technika rozdzielania i oceny składu grupowego frakcji asfaltenowych z utleniania pozostałości próżniowej ropy naftowej
PublicationW pracy opisano wyniki badań nad opracowaniem metodyki oceny składu grupowego i czystości frakcji asfaltenowych techniką chromatografii cienkowarstwowej w normalnych układach faz (NP-TLC). Skupiono się na doborze takich parametrów/warunków rozdzielania, jak stężenie i masa próbki, a także skład i kolejność eluentów stosowanych podczas rozwijania chromatogramów TLC. Zastosowana trój-stopniowa metodyka polega na nałożeniu 5 µL frakcji...
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Determination of high-intensity sweeteners in beverages by high-performance liquid chromatography with mass spectrometry detection.
PublicationThe objective of the present study was to measure the concentration of nine high intensity sweeteners (acesulfame-K, aspartame, alitame, cyclamate, dulcin, neohesperidin dihydrochalcon, neotame, saccharin and sucralose) in different types of beverages available on the polish market. The proposed methodology reported here consists of a extraction with buffer composed of formic acid and N,N-diisopropylethylamine (pH 4.5) followed...
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Release of selected chemical elements from shale drill cuttings to aqueous solutions of different pH
PublicationThe effect of pH changes on leachability of light and heavy metals from shale drill cuttings generated from unconventional shale gas production was investigated. Cuttings, being the primary byproduct generated from drilling operations, belong to the potentially hazardous type of wastes due to presence of heavy and radioactive elements and remains of drilling fluid. In this regard, assessment of potentially dangerous components...
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The lethal effect of hydrotechnical concrete on freshwater Bivalvia
PublicationMost hydrotechnical buildings under construction demand the concrete mixture to be set directly under water. The main reason for such a procedure is to limit the washing away of the the concrete binding mixture and to increase the efficiency of organisation of work so as to ensure continuity in concreting. The impact on the aquatic environment of recent developments in concrete technology and the use of new components has not yet...
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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,...