Wyniki wyszukiwania - Biblioteka Nauki

1

Chromatograf gazowy do celów dydaktycznych i jego zastosowania

100%

Wolska L. , Janicki W. , Konieczka P. , Chrzanowski W. , Namieśnik J.

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2007

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tom T. 12, nr 1

27-32

PL

W artykule opisano zastosowania dydaktyczne prostego chromatografu gazowego, specjalnie opracowanego i zbudowanego do tych celów. Pozwala on na zapoznanie studentów chemii analitycznej z podstawowymi koncepcjami chromatografii a równocześnie prowadzenie ćwiczeń z elementami zaawansowanej metrologii chemicznej. W artykule przedstawiono zasady, jakimi kierowano się przy projektowaniu i budowie aparatu, a także ćwiczenie z bardziej zaawansowanych zagadnień analizy instrumentalnej, do jakich należą kwestie metrologii chemicznej (m.in. wyznaczanie granicy wykrywalności i granicy oznaczalności).

EN

The paper presents a new design of a gas chromatograph, designed and built especially for teaching purposes. It permits the students not only to discover the basic concepts of gas chromatography but also to carry our more sophisticated exercises in chemical metrology, like estimation of limit of detection (LOD), limit of quantification (LOQ) and measuring range.

2

Modyfikacje metod rejestracji w chromatografii gazowej

100%

Michalik A. , Słomkiewicz P. M.

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2007

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tom T. 12, nr 4

131-138

PL

Opisano modyfikację podłączenia przetwornika analogowo-cyfrowego detektora chromatografu gazowego, wyposażonego w złącze szeregowe zgodne z standardem RS-232, do komputera pozbawionego takiego łącza oraz sposób odczytywania danych z chromatogramów, zarejestrowanych na taśmie papierowej i przetwarzania ich w postać cyfrową.

EN

The modification of connection the analogue-digital converter of detector of gas chromatograph to computer without RS-232 interface was described and the methods of the reproduction the data from registered on paper tape chromatograms and transformation these data to the digital form were shown.

3

Simultaneous determination of 223 pesticides in tobacco by GC with simultaneous electron capture and nitrogen-phosphorous detection and mass spectrometric confirmation

80%

Lozowicka B. , Rutkowska E. , Hrynko I.

Open Chemistry

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2015

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tom 13

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nr 1

EN

LSE (liquid-solid extraction), MSPD (matrix solid phase dispersion) and QuEChERS (quick, easy, cheap, effective, rugged and safe) extractions followed by GC-μECD/NPD to determine 223 pesticide residues in tobacco simultaneously were developed and compared. The identities of ten model pesticides were confirmed by GC-MS/MS. The type and amount of dispersant (Florisil, silica gel and alumina), sample mass, cleanup adsorbent, and the eluent (hexane, acetone and acetonitrile) were optimized. Linearity, recovery, LOQ, LOD, and matrix effect were compared. Most recoveries were 71−120% (RSD < 18%). LOD and LOQ were much lower than the CORESTA GRLs. The best method was QuEChERS: acetonitrile extraction and dispersive solid-phase extraction using primary-secondary amine and graphitized carbon.

4

The influence of aniline radicals concentration in the stationary phase on the retention in gas chromatography

80%

Nasuto R.

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1998

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tom Vol. 72, nr 10

2303-2311

EN

Four adsorbents with chemically bounded aniline radicals on silica gel surface of concentration 2.94; 5.86; 6.47 and 7.81 mymole/m(2) were prepared. On packed chromatographic column with unmodified silica gel Si 100 and obtained adsorbents the retention times of aliphatic (C6-C12) and aromatic (benzene, toluene and m-xylene) hydrocarbons and polar organic compounds (chloroform, ethylene chloride, chlorobenzene, p-chlorotoluene and ethyl benzene) were measured. Retention times, obtained on column with packing of the highest concentration of the bounded phase, were shorter than those on column with unmodified silica gel Si 100. Thus, there exists a possibility of optimization of retention of chemical compounds by change of their phase concentration on the support surface.

5

Electron beam irradiation of r-SANEX and i-SANEX solvent extraction systems: analysis of gaseous products

80%

Szreder T. , Kocia R.

Nukleonika

|

2015

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tom 60

|

nr 4

899-905

EN

1-Octanol/kerosene mixtures and water contacted with organic solvents were used as model solutions for r-SANEX and i-SANEX extractions systems. Investigations aimed on a quantitative evaluation of gaseous products generated in these systems under exposure to an electron beam irradiation. Influence of O2, HNO3 and the presence of model ligands and complexes on the radiation chemical yields was studied. Relatively high G(H2) values (up to 420 nmol·J-1) for the organic phase compromise the safety issues of the extraction process and should be considered on the stage of extraction apparatus design. Based on the obtained results gaseous hydrocarbons seem to have negligible impact on safety issue. The upper limit of G(H2) values in water contacted with organic phase was established to be 85 nmol·J-1. This value is relatively low, however, the literature data indicate that G(H2) values measured in aqueous solutions are over twice higher for α-particles irradiation than for electron beam or γ-irradiation. Thus, further investigations of these systems are necessary.

6

Gas chromatography as a tool for determining coal chars reactivity in the process of steam gasification

80%

Smoliński A.

|

2008

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tom Vol. 20, no. 3

349-365

EN

Upgrading of the efficiency of industrial power-production systems and environmental aspects, e.g. reduction of emission of greenhouse gases, is of particular interest to the Polish power sector, inherently depending on its own coal resources and coal processing technologies. Some information on fuel suitability for particular processing technology can be obtained from its reactivity. In this paper a procedure for testing coal chars reactivity, and the results obtained, in the process of steam gasification of coal in a laboratory-scale fixed-bed reactor are presented. The procedure is based on gas chromatographic analysis of a synthesis gas produced in the process. Chemometric methods (for example as hierarchical clustering) enabled discovery of the similarities and dissimilarities of coal samples and investigation of the relationships between the reactivity of coal chars and selected physical and chemical properties important in the steam gasification process.

7

Dozowniki laserowe do chromatografii gazowej

80%

Słomkiewicz P. M. , Witkiewicz Z.

|

2006

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tom T. 11, nr 4

273-280

PL

Opisano konstrukcje nowych dozowników ciekłych próbek, które mogą być wykorzystane w chromatografii gazowej z kolumnami pakowanymi i kapilarnymi. Dozowane próbki są odparowywane bardzo szybko za pomocą promienia laserowego w kontrolowanych warunkach.

EN

The constructions of new injectors of liquid samples for gas chromatography were described. Injected samples are vaporized very quickly by the laser beam in controlled conditions. The injectors are useful for packed and capillary columns.

8

Dozowniki z ruchomymi elementami do chromatografii gazowej

80%

Słomkiewicz P. M. , Witkiewicz Z.

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2007

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tom T. 12, nr 1

6-16

PL

Opisano konstrukcje dozowników do próbek, zawierających anality o małej lotności. Dozowniki te, z ruchomymi igłami, pojemnikami i innymi elementami mogą być wykorzystane w chromatografii gazowej.

EN

The constructions of injectors for samples containing low volatile analytes were described. Those injectors with mobile needles, containers and other elements can be used in gas chromatography.

9

Polyaniline-polypyrrole coating for solid phase microextraction

80%

Vickackaite V. , Ciuvasovaite V.

Open Chemistry

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2007

|

tom 5

|

nr 3

727-738

EN

A procedure for direct electrochemical deposition of polyaniline-polypyrrole blend coating on the surface of stainless steel wire was suggested. Incorporation of polyaniline and polypyrrole into the blend coating was confirmed by infrared spectroscopy. Key parameters (pyrrole, aniline, dopant and sulphuric acid concentrations and deposition potential) influencing the coating’s mechanical stability and surface homogeneity were optimised and thermostability of the coating was investigated. A possibility to apply the coating as a new fibre for solid phase microextraction was demonstrated. The coating showed better selectivity toward aromatic, hydrophobic compounds. [...]

10

Pilot study on feasibility of application of gas chromatography for the assessment of acrylamide concentration in sewage sludge

80%

Włodarczyk E. , Próba M. , Wolny L. , Wojtal Ł.

Acta Biochimica Polonica

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2014

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tom 61

|

nr 2

201-203

EN

The aim of this study was to determine the possibility of using gas chromatography to measurement of the acrylamide concentration in sewage sludge. Acrylamide, as a toxic substance, is not indifferent to human health, but it is used in the production of plastics, dyes, adhesives, cosmetics, mortar, as well as a coagulant for water treatment, wastewater or sewage sludge conditioning. Determination of acrylamide by gas chromatography was based on standard: EPA Method 8032A "Acrylamid by gas chromatography." It consists of a bromination reaction of the compound in the presence of dibromopropendial derivative, a triple extraction with the ethyl acetate, a concentration of the eluate sample up to the 1 ml volume, and an analysis by the gas chromatography using an electron capture detector (ECD). The acrylamide concentration of was calculated according to the formula presented in the mentioned standard. All samples were performed twice (the difference between the results was not greater than 10%), and the average value of the four samples was 17.64 µg/L−1. The presence of acrylamide in sewage sludge has been confirmed.

11

Gas chromatographic determination of diethylene glycol in workplace air

80%

Politowicz M. , Pośniak M.

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1998

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tom No. 8

154-161

EN

A capillary gas chromatographic method with flame-ionization detection has been developed for determination of diethylene glycol (DEG) aerosols at concentrations between 2.5 to 30.0 mg m-3 in work-place air. Polypropylene filters were used to sample DEG aerosols from air; the recovery was 90%. The working temperature and carrier gas flow rate used for gas chromatography were optimized to enable separation of DEG from solvent and other compounds present in industrial air. The detection limit was 50 ng on-column.

12

Wykorzystanie chromatografu gazowego w połączeniu z zestawem kilku detektorów w praktyce analitycznej

70%

Dąbrowski Ł.

|

2007

|

tom R. 15, nr 1

18-23

PL

Analiza próbek rzeczywistych może nastręczać trudności podczas interpretacji uzyskanych chromatogramów. Niekorzystne zjawiska i efekty występujące w trakcie analizy próbek (koelucja, zmiana czasów retencji itp.) wymuszają konieczność przeprowadzania dodatkowej identyfikacji analitów (np. przez wykonanie analizy z użyciem kolumny o innej polarności lub zastosowanie układu sprzężonych detektorów). Układ kilku (z reguły dwóch) detektorów umożliwia jednoczesną analizę eluatu z wykorzystaniem odrębnych zjawisk fizykochemicznych będących podstawą działania danego detektora. Praktyczne wykorzystanie układów dwóch detektorów do analizy próbek rzeczywistych jest jednak niewielkie. Mimo bezspornych zalet (możliwość potwierdzenia identyfikacji substancji na chromatogramie), podłączenie dodatkowego detektora wiąże się z koniecznością pracy w nieco bardziej skom-plikowanym układzie chromatograficznym. W pracy przedstawiono wybrane aspekty techniczne pracy w układzie wielodetektorowym oraz przykładowe aplikacje analizy próbek rzeczywistych.

EN

Real sample analysis by gas chromatography could lead to many unwanted effects (i,e. coelution, retention time shift etc.). To avoid the identification problems, additional analysis of the compounds with more polar capillary column or multidetector system is needed. Multidetector (usually dual-detector) system enables a simultaneous analysis of the sample components using different physicochemical phenomena. Although there is a quite easy task to connect two or more detectors in a multidetector system, such solutions are in a relatively rare usage. In this work some technical aspects of mutidetector system setup and some applications are presented.

13

PURITY DETERMINATION OF THE STARTING MATERIALS USED IN THE SYNTHESIS OF PHARMACEUTICAL SUBSTANCES

70%

Groman A. , Stolarczyk E. , Mucha M.

Acta Poloniae Pharmaceutica - Drug Research

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2019

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tom 76

|

nr 1

29-35

EN

High requirements on the API quality mean that the quality control of the starting material is crucial to the manufacturing process of drug substances. Three sensitive methods for the purity determination of the following starting materials: ethylene glycol (method I), 3-acetylpyridine (method II) and 4-chloromethyl-5-methyl-1,3-dioxol-2-one (method III) used in the synthesis of selected drug substances were developed using GC-FID techniques. All the methods were validated according to the International Conference on Harmonization guidelines. The correlation coefficient values were found about 0.99. The obtained RSD values from the replicate injections in the range of 20 - 120% of the nominal concentration ensured the precision.

14

Application of GC and modulated ECD for the determination of SF5CF3 mixing ratios in the atmosphere

70%

Rosiek J. , Lasa J. , Śliwka I. , Różański K.

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2007

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tom Vol. 52, No. 2

235-242

EN

ECD detectors, operated in the solute-switching mode, have been developed for determina- , tion of SF5CF3 mixing ratios in the atmosphere. Special home-made modulator-detector system equipped with two ECD detectors and a 63Ni source has been constructed. The constructed system enabled one to achieve the detection limit of 0.23 ppqv** for SF5 CF, in air samples of the initial volume of 200 cm 3. The system was adopted for regular measurements of SF5CF3 in air.

PL

Przedstawiono zastosowanie dwóch detektorów ECD pracujących w systemie modulacyjnym do analizy SF5CF3. Zestaw modulator-detektor wyposażony w źródła promieniotwórcze 63Ni został wykonany we własnym zakresie. Granica wykrywalności SF5CF3 w próbce powietrza o początkowej objętości 200 cm3 wynosi 0,23 ppqv** . Opracowany układ został zastosowany do pomiaru stężenia SSF5CF3, w powietrzu.

15

Zastosowanie chromatografii gazowej w badaniu adsorbentów i katalizatorów : eksperymentalne metody charakterystyki adsorbentów i katalizatorów

70%

Sarbak Z.

|

2004

|

tom R. 9, nr 1

22-26

PL

W pierwszej części artykułu, dotyczącego wykorzystania chromatografii gazowej, opisano oznaczanie różnych parametrów fizykochemicznych, charakteryzujących adsorbenty i katalizatory. W obecnie prezentowanym artykule skupiono się nad zastosowaniem chromatografii gazowej w badaniach aktywności i kinetyki reakcji katalitycznej.

16

Oznaczanie migracji eta-Caprolaktamu z wyrobów z tworzyw sztucznych metodą chromatografii gazowej

70%

Groman A. , Guberska J.

|

1999

|

tom T. 44, nr 9

618-622

PL

Opracowana metoda dotyczy migracji eta-kaprolaktamu (KL) z wyrobów z tworzyw sztucznych kontaktujących się z żywnością do różnych wodnych płynów modelowych (woda, roztwory alkoholu etylowego - 15-proc. i kwasu octowego - 3-proc.)- Jako wzorzec wewnętrzny zastosowano 1,6-heksa-nodiol. W określonych warunkach, czasy retencji (t,) KL i 1,6-heksanodiolu wynosiły odpowienio 19,4 i 17,2 min (rys. 1). Opracowano również warunki oznaczania migracji KL do oleju słonecznikowego (ekstrakcja wodą, dodanie wzorca wewnętrznego do oleju przed ekstrakcją). Wykrywalność opracowanych metod wynosi 3 mg/kg płynu modelowego, podczas gdy limit migracji specyficznej w przypadku KL jest równy 15 mg/kg. Błąd względny opisanych metod nie przekracza 10%, a względne odchylenie standardowe RSDr jest mniejsze niż 8.

EN

eta-Caprolactam migrated from plastic packaging materials into food simulants (water, aqueous 15% ethanol, and aqueous 3% acetic acid) was determined by GC. 1,6-Hexanediol was used as the internal standard. Under specified conditions, the retention times of s-caprolactam and 1,6-hexanediol were 19.4 and 17.2 min, respectively (Fig. 1). Migration of eta-caprolactam into sunflower oil (extraction with water and addition of the internal standard prior to the extraction) was also studied. The detectability of the method was found to be 3 mg/kg food simulant. For eta-caprolactam, the specific migration limit is 15 mg/kg. The relative error of the method was found to be maximum 10%, and the relative standard deviation was lower than 8.

17

Wykorzystanie parametrów fizykochemicznych i metod chromatografii gazowej w badaniach i rozróżnieniu podstawowych olejów mineralnych

70%

Fall J. , Voelkel A.

|

2006

|

tom R. 14, nr 4

164-170

PL

W pracy zaproponowano metodę klasyfikacji olejów podstawowych (zgodnie z klasyfikacją API) w oparciu o oznaczone (w temperaturze 20 stopni Celsjusza) wartości gęstości i współczynnika załamania światła. W tym przypadku ilość próbki niezbędnej do wykonania tych oznaczeń wynosi ok. 3-5 g. Dodatkowo przedstawiono wyniki badań uzyskane metodą odwróconej chromatografii gazowej.

EN

Variety of refinery processes used in the production of base mineral oils results in the presence of oils with different group composition and chemical structure. API classification allows to attribute the oils to given group basing on the values of: saturates content, sulfur content and viscosity index. Determination of these parameters requires 30-40g sample what for environmental samples is often impossible. Another classification procedure for the base oils (in agreement with API) based on the values of the density and refractive index of the examined oil (at 20 stopni Celsjusza) has been proposed. Required amount of the sample is limited to 3-5g. Examined oils were also characterized by inverse gas chromatographic method.

18

Polycyclic aromatic hydrocarbon in African Giant Snail (Archachatina marginata (Swainson, 1821))

70%

Ikwuagwu P. , Bassey F. I. , Iwegbue C. M. A.

World News of Natural Sciences

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2023

|

tom 46

113-127

EN

The concentrations of polycyclic aromatic hydrocarbons (PAHs) were examined in African Giant Snail samples collected from five snail farms in Etche Local Government Area, Port Harcourt, Rivers State, Nigeria. With the view to providing information on the health risks to humans from the consumption of these foods. The concentrations of PAHs were measured by means of Gas Chromatography Mass Spectrophotometer (GC-MS). The results obtained from the analysis showed that the concentrations of 16 PAHs in the snails ranged from 0.04 to 4.148 mg/kg. The dominant PAHs compounds in the snail species were 3-, 5- and 7- rings PAHs which are phenanthrene, benzo(b)fluoranthrene and indeno(1,2,3-cd)pyrene which suggests worrisome pollution levels of the soil and environment of Port Harcourt Nigeria. The findings of this study thus point to the need for improved caution in the consumption of snails harvested from the study area. It is expected that this will help to improve public health awareness and practice.

19

Studies on carcinogenic PAHs emission generated by vehicles and its correlation to fuel and engine types

70%

Kumar V. , Kothiyal N. C. , Saruchi

Polish Journal of Chemical Technology

|

2014

|

tom 16

|

nr 1

48-58

EN

The objective of this study was to find major PAHs produced in ambient air from the automobile exhaust as a function of fuels (diesel, petrol, and biodiesel) and engine type qualitatively and quantitatively. The recovery range was found between 30% and 70%. The study was carried out on two, three, and four wheelers. Biodiesel samples tested in the study were synthesized indigenously from different starting raw materials and analyzed for PAHs concentration in the exhaust on a Honda genset (EBK 2000AC Model). Biodiesel samples were blended with diesel in different ratio (25:75, 35:65 and 45:55) to investigate the exhaust behavior. Biodiesel was blended with Diesel the concentration of almost all PAHs reduces in comparison to pure Diesel exhaust. B(a)A and B(a) P was the common PAH found in higher concentration in almost all fuels. FTIR results indicate esterification of vegetable oil and NMR results indicate a complete conversion of oils into biodiesel.

20

Lotne kwasy tłuszczowe na składowisku odpadów - występowanie i oznaczanieLotne kwasy tłuszczowe na składowisku odpadów - występowanie i oznaczanie

60%

Banel A. , Zygmunt B.

|

2009

|

tom Vol. 16, nr 2

193-206

PL

Lotne kwasy tłuszczowe (LKT) powstają podczas biodegradacji materii organicznej i dlatego są także obecne na składowiskach odpadów, gdzie odgrywają kluczową rolę w przetwarzaniu materii organicznej w metan. Optymalizacja tego procesu wymaga znajomości i kontroli stężenia LKT, a ponieważ mają one również negatywny wpływ na środowisko, ich zawartość powinna być monitorowana w odciekach surowych i oczyszczonych oraz ich odbieralnikach (woda powierzchniowa, gleba, powietrze). W próbkach o tak szerokiej gamie matryc najodpowiedniejszą techniką omaczania LKT wydaje się być chromatografia gazowa, pod warunkiem, że próbka jest właściwie przygotowana do analizy. Polega to najczęściej na izolacji i wzbogacaniu przed wprowadzeniem do chromatografu gazowego, chocia1: bezpośrednie dozowanie próbek wodnych może też być stosowane, jeżeli stężenia są odpowiednio duże.

EN

Volatile fatty acids (VFAs) are formed in the process of biodegradation of organic matter and therefore they are commonly present in municipal solid waste landfills, where they play a crucial role in converting organic matter to methane. Optimization of this process needs the knowledge and control of VFA content. Since VFAs also have a negative effect on the environment quality their content should be measured also in raw and treated leachate surface and groundwater and air in the area of the landfill. The most appropriate technique to determine individual VFAs is gas chromatography. The samples must be properly prepared before they can be introduced into GC for analysis. The sample preparation is generally based on VFA isolation, often accompanied by enrichment; though aqueous samples, after suspended matter removal, can also be injected to same GC systems.