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Wyniki wyszukiwania dla: ANALYTICAL CHEMISTRY
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Analytical applications of smartphones for agricultural soil analysis
PublikacjaSoil is one of the most important farming resources. Appropriate managing of its quality promotes productive and sustainable agriculture. The valuable farm practice in soil quality managing is based on regular soil analysis with the aim to determine the exact amount of nutrients or other chemical, physical and biological soil properties. Soil analysis usually requires samples collection at desired sampling depth following by samples...
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Novel fast analytical method for indirect determination of MCPD fatty acid esters in edible oils and fats based on simultaneous extraction and derivatization
PublikacjaA novel method for indirect determination of MCPD esters levels in lipid samples has been developed. The method is based on combination of extraction and derivatisation in the same sample preparation step. It is achieved by the application of diethyl ether as extraction solvent for isolation of released from esterified forms analytes from water phase and dilution solvent for solid PBA – derivatisation agent. It is a noteworthy...
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Development and validation of an eco-compatible UV–Vis spectrophotometric method for the determination of Cu2+ in aqueous matrices
PublikacjaCu 2+ are ubiquitous ions in the ecosystem and are responsible of serious environmental pollution. Indeed, the development of sensitive methods for Cu 2+ detection is an urgent demand. In this work, we proposed a new spectrophotometric method for Cu 2+ determination in different water matrices (distilled water, drinking water, wastewater, and river water). The method employs a bio-based organic ligand namely tetrasodium iminodisuccinate...
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Monitoring and analytics of semivolatile organic compounds (SVOCs) in indoor air
PublikacjaThis paper reviews literature information on the behaviour of semivolatile organic compounds (SVOCs) in the indoor environment, as well as the most likely emission sources. The consecutive stages of analytical procedures used for monitoring SVOCs in indoor environments are described. The most common approaches used for collecting samples from the gas and particulate phases are mentioned. The paper discusses and compares various...
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The home-made in situ passive flux sampler for the measurement of monoterpene emission flux: preliminary studies
PublikacjaThe paper presents the construction and metrological characteristics of the home-made in situ passive flux sampler, an analytical tool representing small-scale emission chambers working in situ and passively sampling analytes from the gaseous phase. The sorption element was a cylindrical container made of stainless steel net, packed with a carbon sorbent bed-graphitized charcoal, Carbograph 4 (35/50mesh). The recommended working/exposure...
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Hanging drop cathode-atmospheric pressure glow discharge as a new method of sample introduction for inductively coupled plasma-optical emission spectrometry
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A new approach for the extraction of tetracyclines from soil matrices: application of the microwave-extraction technique
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Ionic liquids for the passive sampling of sulfonamides from water—applicability and selectivity study
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Preliminary study on suitability of ionic liquids as potential passive-sampling media of polyaromatic-hydrocarbon (PAH) analyses in water
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Metal-coated fused silica fibers as a support for immobilized compounds yielding a volatile analyte (C2H4)
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Determination of tributyltin in marine sediment: Comit� Consultatif pour la Quantit� de Mati�re (CCQM) pilot study P-18 international intercomparison
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Determination of tributyltin (TBT) in marine sediment using pressurised liquid extraction–gas chromatography–isotope dilution mass spectrometry (PLE–GC–IDMS) with a hexane–tropolone mixture
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Theoretical opportunities and actual limitations of pH gradient HPLC
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New approach based on solid-phase extraction for the assessment of organic compound pollutions in so-called pharmaceutically pure water
PublikacjaOpisano mozliwość zastosowania nowej procedury analitycznej opartej na wykorzystaniu techniki ekstrakcji do fazy stałej (na etapie izolacji i wzbogacania analitów) do oznaczania śladowych ilości zanieczyszczeń organicznych w wodzie specjalnej czystości używanej do celów farmaceutycznych.Próbka badanej wody jest przepuszczana przez złoże sorbenta, które jest osuszane za pomocą strumienia oczyszczonego powietrza, przed etapem termicznej...
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Determination (monitoring) of PAHs in surface waters: why operationally defined procedure is needed
PublikacjaW pracy przedstawiono i skomentowano rezultaty badań międzylaboratoryjnych oznaczania wielopierścieniowych węglowodorów aromatycznych w wodzie czystej i wodzie zawierającej zawiesinę. Badania wskazują, ze wyniki oznaczania zależa od zastosowanej techniki izolacji analitów z próbki i końcowej procedury ich rozdzielania i oznaczania. Przeprowadzone badania wskazują, że nowoczesna analityka nie dysponuje technikami izolacji, które...
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A comparison of three solvent-free techniques coupled with gas chromatography for determining trihalomethanes in urine samples
PublikacjaDążenie do oznaczania lotnych analitów organicznych w próbkach płynów biologicznych charakteryzujących się złożonym, a często zmiennym składem matrycy, stanowi siłę napędową do działań analityków w zakresie poszukiwania nowych rozwiązań metodycznych i aparaturowych. Publikacja ta przedstawia porównanie trzech technik zastosowanych do tych celów: technikę analizy fazy nadpowierzchniowej z generacją strumienia ciekłego sorbentu...
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Determination of tributylotin (TBT) in marine sediment using pressurised liquid extraction-gas chromatography-isotope dilution mass spectrometry (PLE-GC-IDMS) with a hexane-tropolone mixture
PublikacjaOpracowano metodę oznaczania zawartości tributylocyny w próbkach osadu morskiego. Na etapie izolacji zastosowano technikę przyspieszonej ekstrakcji za pomocą roztworu tropolonu w heksanie.Na etapie oznaczeń końcowych wykorzystano technikę chromatografii gazowej, stosując metodę spektrometrii mas rozcieńczenia izotopowego. Wyznaczono parametry walidacyjne opracowanej metody: granicę wykrywalności, precyzję, poprawność i niepewność.
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Metal-coated fused silica fibres as a support for immobilized compounds yielding a volatile analyte (C2H4)
PublikacjaPrzedstawiono wyniki badań dotyczących wykorzystania chemicznie modyfikowanych włókien szklanych pokrytych warstwą metalu (aluminium), jako nośników związków powierzchniowych. W trakcie procesu termicznego rozkładu z tak zmodyfikowanych włókien uwalnia się eten, który stanowi składnik mierzony uzyskiwanej gazowej mieszaniny wzorcowej. Ilość uwalnianego etenu zależy jedynie od długości danego rodzaju i typu modyfikowanego włókna...
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Electroanalytical and spectroscopic procedures for examination of interactions between double stranded DNA and intercalating drugs
PublikacjaPrzedstawiono metodę elektrochemicznego opisu oddziaływań dsDNA ze związkiem biologicznie czynnym w warunkach, w których zarówno badany związek jak i cząsteczka DNA są w roztworze elektrolitu. Opracowano warunki pomiaru, gdzie ani związek, ani DNA nie adsorbuje na elektrodzie. Wykazano, podobnie jak podczas badania innymi metodami, że oddziaływania są dwojakiego rodzaju: elektrostatyczne i poporzez interkalację.
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Passive sampling as a tool for obtaining reliable analyticalinformation in environmental quality monitoring
PublikacjaSpośród technik pobierania próbek analitów technika dozymetrii pasywnej wydaje się być interesującą alternatywą w stosunku do powszechnie stosowanych technik dynamicznych. Dozymetria pasywna łączy w sobie etap pobierania próbki z etapem izolacji i wzbogacania analitów, które są zatrzymywane w odpowiednim medium zatrzymującym. Prowadzi to do znacznego uproszczenia operacji analitycznych wykonywanych in situ. W odróżnieniu od aktywnych...
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Determination of nine high-intensity sweeteners in various foods by high-performance liquid chromatography with mass spectrometric detection
PublikacjaAn 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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Oil refinery dusts: morphological and size analysis by TEM
PublikacjaThe objectives of this work were to develop a means of sampling atmospheric dusts on the premises of an oil refinery for electron microscopic study to carry out preliminary morphological analyses and to compare these dusts with those collected at sites beyond the refinery limits. Carbon and collodion membranes were used as asupport for collection of dust particles straight on transmission electron microscopy (TEM) grids. Micrographs...
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Hydrolytical instability of hydroxyanthraquinone glycosides in pressurized liquid extraction
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The state-of-the-art determination of urinary nucleosides using chromatographic techniques “hyphenated” with advanced bioinformatic methods
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New approaches to chromatographic determination of lipophilicity of xenobiotics
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A simple graphene-based pipette tip solid-phase extraction of malondialdehyde from human plasma and its determination by spectrofluorometry
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Passive sampling and/or extraction techniques in environmental analysis: a review
PublikacjaThe current state-of-the-art of passive sampling and/or extraction methods for long-term monitoring of pollutants in different environmental compartments is discussed in this review. Passive dosimeters that have been successfully used to monitor organic and inorganic contaminants in air, water, sediments, and soil are presented. The application of new approaches to the determination of pollutants at the sampling stage is discussed....
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An evaluation of sucrose as a possible contaminant in e-liquids for electronic cigarettes by hydrophilic interaction liquid chromatography–tandem mass spectrometry
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Exploration of optical fibres as a carrier for new benzene and toluene matrix-free reference materials
PublikacjaTo meet high expectations concerning precision and accuracy of reference materials, preparation of matrixfree reference materials using thermal decomposition-gas chromatography-mass spectrometry (TD-GC-MS) was proposed in this study. In the paper, the results obtained in preparation of the new reference materials for benzene and toluene are presented, based on the thermal decomposition technique of compounds chemically bound to...
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Rapid ion-exchange matrix removal for a decrease of detection limits in the analysis of salt-rich reservoir waters for fluorobenzoic acids by liquid chromatography coupled with tandem mass spectrometry
PublikacjaA matrix removal procedure with ion-exchange resin prior to analysis for 18 fluorinated benzoic acids (FBAs) tracers in saline (>25% salt) reservoir water was optimized. The elimination of >98% of salt and the simultaneous matrix sample cleanup allowed the direct analysis using the supernatant by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). This resulted in a gain in detection limits for most of the tracers...
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Optimization of capillary isotachophoretic method for determination of major macroelements in blue honeysuckle berries (Lonicera caerulea L.) and related products
PublikacjaA reliable and repeatable isotachophoretic method for the simultaneous determination of K+, Na+, Ca2+, Mg2+ and ammonium in berries of different blue honeysuckle cultivars was developed. The usefulness of the complex-forming equilibria in determining the cations mentioned above was studied. The addition of 7.5 mM 18-crown-6 and 2 mM α-hydroxyisobutyric acid to sulfuric acid enhanced the separation capacity of the leading electrolyte....
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Improvement of derivatized amino acid detection sensitivity in micellar electrokinetic capillary chromatography by means of acid-induced pH-mediated stacking technique
PublikacjaDerivatization is a frequently used sample prepara-tion procedure applicable to the enhancement of analyte de-tection sensitivity. Amino acids mostly require derivatization prior to electrophoretic or chromatographic analysis, especial-ly if spectrophotometric detection is used. This study presents an on-line preconcentration technique for derivatized amino acids. The sensitivity of the method was improved by the utilization of...
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An evaluation of sucrose as a possible contaminant in e-liquids for electronic cigarettes by hydrophilic interaction liquid chromatography–tandem mass spectrometry
PublikacjaThe influence of sucrose combustion products on smoking and nicotine addiction is still controversial because the presence of the sucrose may be treated as a source of aldehydes and organic acids. In e-liquids used as refills for electronic cigarettes, which are made primarily of poly(propylene glycol), glycerine and ethanol, sucrose may be present at trace levels, and its impact on mainstream smoke formation, and hence on human...
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Elucidation of transformation pathway of ketoprofen, ibuprofen, and furosemide in surface water and their occurrence in the aqueous environment using UHPLC-QTOF-MS
PublikacjaThe identification and determination of transformation products (TPs) of pharmaceuticals is essential nowadays, in order to track their fate in the aqueous environment and, thus, to estimate the actual pollution. However, this is a challenging task due to the necessity to apply high-resolution instruments enable to detect known and unknown compounds. This work presents the use of liquid chromatography quadrupole time-of-flight...
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A new procedure for the determination of distillation temperature distribution of high-boiling petroleum products and fractions
PublikacjaThe 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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Solventless sample preparation techniques based on solid- and vapour-phase extraction
PublikacjaThe main objective of this review is to critically evaluate recent developments in solventless sample preparation techniques. The potential of a variety of sample preparation techniques based on solid- and vapour-phase extraction techniques is evaluated. Direct thermal extraction and derivatization processes to facilitate the extraction of analytes in different areas are included. The applicability, disadvantages and advantages...
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Enzymatic electrodes nanostructured with functionalized carbon nanotubes for biofuel cell applications
PublikacjaNanostructured bioelectrodes were designed and assembled into a biofuel cell with no separating membrane.
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Evaluation of polycaprolactone as a new sorbent coating for determination of polar organic compounds in water samples using membrane–SPME
PublikacjaCommercially available solid-phase microextraction fibers used for isolation of polar analytes are based on the adsorption phenomenon. In consequence, typical limitations bonded with analytes displacement and matrix effects are very frequent. In the present study, alternative solution is described. Polycaprolactone (PCL) was used for the first time as sorbent to isolate polar organic compounds from water samples using the membrane–solid-phase...
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Determination of eight artificial sweeteners and common Stevia rebaudiana glycosides in non-alcoholic and alcoholic beverages by reversed-phase liquid chromatography coupled with tandem mass spectrometry.
PublikacjaThe method for the determination of acesulfame-K, saccharine, cyclamate, aspartame, sucralose, alitame, neohesperidin dihydrochalcone, neotame and five common steviol glycosides (rebaudioside A, rebaudioside C, steviol, steviolbioside and stevioside) in soft and alcoholic beverages was developed using high-performance liquid chromatography and tandem mass spectrometry with electrospray ionisation (HPLC-ESI-MS/MS). To the best of...
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Protein overproduction alters exosome secretion in Chinese hamster ovary cells
PublikacjaDespite the abundance of available cell lines, nearly 70% of all recombinant therapeutic proteins today are produced in Chi-nese hamster ovary (CHO) cells. The impact of protein overproduction on the secretion of exosomes by CHO cells has been investigated here. Increased secretion of extracellular vesicles (EVs) by protein overexpressing CHO cells was demonstrated with protein content assay, nanoparticle tracking analysis, and...
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Plant-based meat substitute analysis using microextraction with deep eutectic solvent followed by LC-MS/MS to determine acrylamide, 5-hydroxymethylfurfural and furaneol
PublikacjaFor the analysis of plant-based meat substitutes and the determination of Maillard reaction products such as acrylamide, 5-hydroxymethylfurfural and furaneol, a novel and effective procedure based on hydrophobic natural deep eutectic solvent and liquid chromatography coupled with tandem mass spectrometry was developed for the first time. The 49 compositions of the deep eutectic solvents were designed and screened to select the...
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A nontargeted approach to determine the authenticity of Ginkgo biloba L. plant materials and dried leaf extracts by liquid chromatography-high-resolution mass spectrometry (LC-HRMS) and chemometrics
PublikacjaThe lack of stringent regulations regarding raw materials for herbal supplements used for medicinal purposes has been a constant challenge in the industry. Ginkgo biloba L. leaf extracts attract consumers because of the supposed positive effect on mental performance and memory. Supplements are produced using dried leaf materials and standardized leaf extracts such as EGb 761. Adulteration of Ginkgo biloba L. plants and extracts...
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Development and validation of a method for the simultaneous analysis of fatty acid ethyl esters, ethyl sulfate and ethyl glucuronide in neonatal meconium: application in two cases of alcohol consumption during pregnancy
PublikacjaAlcohol consumption during pregnancy constitutes one of the leading preventable causes of birth defects and neurodevelopmental disorders in the exposed children. Fatty acid ethyl esters (FAEEs), ethyl glucuronide (EtG) and ethyl sulfate (EtS) have been studied as potential biomarkers of alcohol consumption. However, most analytical approaches proposed for their analysis in meconium samples consist of separated extraction procedures...
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Stabilities of bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, and their derivatives under controlled conditions analyzed using liquid chromatography coupled with tandem mass spectrometry
PublikacjaBisphenol A diglycidyl ether (BADGE), bisphenol F diglycydyl ether (BFDGE), and their related compounds are widely used as precursors in production of epoxy resins. The high reactivity of these compounds makes the development of analytical methodologies that ensure appropriate metrological accuracy crucial. Consequently, we aimed to determine whether and to what extent the composition of the solution and storage conditions affect...
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Sample preparation procedure for the determination of polycyclic aromatic hydrocarbons in petroleum vacuum residue and bitumen
PublikacjaThis paper describes a novel method of samplepreparation for the determination of trace concentrations ofpolycyclic aromatic hydrocarbons (PAHs) in high-boilingpetroleum products. Limits of quantitation of the investigatedPAHs in materials of this type range from tens ofnanograms per kilogram to <20 μg/kg. The studies revealedthat in order to separate most of interferences from theanalytes without a significant loss of PAHs, it...
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Determination of chlorinated solvents in industrial water and wastewater by DAI- GC-ECD
PublikacjaA very simple and quick analytical method, basedon direct aqueous injection, for determination of halogenatedsolvents in refinery water and wastewater, is described.There is a need to determine halogenated solvents in refinerywater streams, because they may originate from severalprocesses. There is also a need to develop methods enablingVOX to be determined in samples containing oil fractions.The method described enables simultaneous...
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Application of headspace-solid phase microextraction followed by gas chromatography-mass spectrometry to determine short-chain alkane monocarboxylic acids in aqueous samples
PublikacjaCelem prowadzonych badań było opracowanie metodyki oznaczania krótkołańcuchowych kwasów alkanomonokarboksylowych (KKA), opartej na ich izolowaniu i wzbogacaniu za pomocą techniki HS-SPME, a następnie oznaczaniu za pomocą chromatografii gazowej sprzężonej ze spektrometrią mas (GC-MS). Do ekstrakcji zastosowano włókno pokryte polarną fazą stacjonarną opartą na glikolu polietylenowym (PEG). Dla celów porównawczych zastosowano również...
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Determination of organotin compounds in biological samples using accelerated solvent extraction, sodium tetraethylborate ethylation, and multicapillary gas chromatography flame photometric detection.
PublikacjaPrzedstawiono metodę oznaczania związków cynoorganicznych w próbkach biologicznych. Procedura oparta jest na wykorzystaniu ekstrakcji pod zwiększoną temperaturą i ciśnieniem (ASE) do izolacji związków cynoorganicznych z próbek wątroby morświnów odłowionych w Morzu Bałtyckim. Walidacji metody dokonano na podstawie analizy materiału odniesienia NIES No 11.
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Derivatisation in gas chromatographic determination of acidic herbicides inaqueous environmental samples.
PublikacjaW pracy przedstawiono przegląd literaturowy dotyczący wykorzystania derywatyzacji w oznaczaniu herbicydów kwasowych w wodnych próbkach środowiskowych za pomocą chromatografii gazowej. Omówiono główne typy reakcji (transestryfikacja, estryfikacja, sililowanie, alkilacja, alkilacja ekstraktywna i pirolityczna), które powodują utworzenie pochodnych, łatwych do analizy techniką chromatografii gazowej. Scharakteryzowano także...
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Intercomparison on measurements of PCBs in pork fat during the Belgian PCB-crisis
PublikacjaW pracy przedstawiono wyniki porównania międzylaboratoryjnego oznaczania PCB w tłuszczu wieprzowym. Porównanie międzylaboratoryjne przeprowadzono w związku z tzw. "belgijskim kryzysem PCB" w latach 1999-2000. W porównaniu uczestniczyło 31 laboratoriów. Materiałem do badań były wyprodukowane w Instytucie Metod i Pomiarów Odniesienia (IRMM) w Geel - Belgia, trzy materiały odniesienia zawierające PCB w tłuszczu wieprzowym (suma PCB...