Wyniki wyszukiwania - Biblioteka Nauki

1

Solid phase extraction in food analysis

100%

Majewska M. , Krosowiak K. , Raj A. , Smigielski K.

Zeszyty Naukowe. Politechnika Łódzka. Chemia Spożywcza i Biotechnologia

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2008

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tom 72

2

Magnetic molecular imprinted polymers as a tool for isolation and purification of biological samples

88%

Kwaśniewska K. , Gadzała-Kopciuch R. , Buszewski B.

Open Chemistry

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2015

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tom 13

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nr 1

EN

Technology of molecularly imprinted polymers (MIP) has become very popular in recent decades. MIPs are primarily used in medical diagnostics, chromatographic separation and solid phase extraction (SPE); also as sensors and catalysts. In recent years there have been reported benefits of combining molecular imprinted polymers with additional features, e.g. magnetic properties, through the build-up of this type of material on magnetite particles (Magnetic Molecularly Imprinted Polymer – MMIP). This method produces a multifunctional material which has high selectivity and the ability to isolate the analyte from biological and environmental samples, allowing effective purification from such interferents as proteins and fats. This developing branch of new materials for the preparation and purification of complex sample matrices is an interesting alternative to materials routinely used to date, particularly with regard to the immunosorbents. This paper summarizes recent reports regarding MMIP preparation and their application for purification and isolation of compounds from biological matrices.

3

Determination of di-n-butyl Phthalate in Environmental Samples

88%

Ziembowicz S. , Kida M.

Rocznik Ochrona Środowiska

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2023

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tom Tom 25

242--249

EN

A devised methodology presented here allows the determination of di-n-butyl phthalate in environmental samples (water and landfill leachate) using solid-phase extraction (SPE) and gas chromatography. It is developed based on the use of a gas chromatograph with an FID detector. Preliminary testing has also provided extraction parameters and conditions for chromatographic determination, with calibration applied by reference to an internal standard. The linearity of the calibration curve has been tested in DBP concentrations ranging from 0 to 7.5 mg/L, with the data obtained showing that, throughout this range, the detector readings as a function of the DBP concentrations remain linear (R2 coefficient >0.99). The average levels of recovery of DBP from aqueous solutions of phthalates are in the range of 97-109%, while the corresponding figures for leachates are 85-101%. The values of the coefficients of variation associated with the results obtained do not exceed 5%. The results, therefore, indicate that the applied extraction method is effective as regards DBP extraction from both water and landfill leachate, while numerous other substances present in the leachate from landfill sites apparently do not affect the correct determination of di-n-butyl phthalate by the method developed.

4

Aryl chemically bonded phases for determination of selected polycyclic aromatic hydrocarbons isolated from environmental samples utilizing SPE-HPLC

75%

Gadzala-Kopciuch R. M. , Kluska M. , Welniak M. , Kroszczynski W. , Buszewski B.

Polish Journal of Environmental Studies

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1999

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tom 08

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nr 6

EN

A method for the preparation and application of aryl chemically bonded phases designed for SPE/HPLC determination of polycyclic aromatic hydrocarbons (PAHs) in environmental samples is described. New adsorbents have been characterised by different physicochemical techniques (porosimetry, CHN and chromatographic analysis). The sorption properties of prepared packings were investigated by the determination of sorption isotherms (so-called breakthrough curves). A comparison of the recovery rates (R) of selected PAHs for new packings and for conventional material C8 has been performed.

5

Isolation of pesticides from water matrix using off-line extraction techniques

75%

Gorna-Binkul A. , Bartczak D. , Gadzala R. M. , Shintani H. , Buszewski B.

Polish Journal of Environmental Studies

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1996

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tom 05

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nr 6

EN

The process of the isolation of malathion from water matrix has been optimized from the point of recovery. Solid phase extraction (SPE) columns with different material packings have been used to study the dependence of recovery on adsorbent type, structure and character. Solid membrane EMPORE with C-18 groups has also been used for this investigation. Comparison of extraction efficiency obtained for SPE column and extraction disc has been done.

6

Voltammetric determination of Aclonifen at a silver amalgam electrode in drinking and river water

63%

Novotný V. , Barek J.

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2017

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tom Vol. 24, nr 2

277--284

EN

A method for the determination of pesticide Aclonifen (AC) in drinking and river water by differential pulse voltammetry (DPV) on a meniscus modified silver solid amalgam electrode (m-AgSAE) using solid phase extraction (SPE) as a cleanup and preconcentration procedure is described. The limit of detection (LOD) for direct DPV determination of AC in deionized water is 2.7·10-8 mol·dm-3. LOD for DPV determination of AC in tap water after SPE is 1.6·10-10 mol·dm-3, the recovery being 55%. LOD for the determination of AC in Vltava river water is 1.9·10-9 mol·dm-3, the recovery being 65%. Humic acids interfere with the determination in river water; this problem can be resolved by adjusting the pH of the extracted sample to 6. The advantages of this approach are high sensitivity, low LOD, quick and easy sample preparation and fast determination.

7

Influence of geosmin, dimethyl trisulfide, 2- and 3-methylbutan-1-ol on raw spirits quality

63%

Biernacka P. , Plutowska B. , Wardencki W.

Nauka Przyroda Technologie. Uniwersytet Przyrodniczy w Poznaniu

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2009

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tom 03

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nr 4

8

Investigation of metallothionein concentration with preconcentration by solid phase extraction on covalent affinity chromatography gel for quantitative determination of exposure to heavy metals

63%

Kabzinski A. K. M.

Polish Journal of Environmental Studies

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1996

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tom 05

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nr 5

EN

The aim of this study was to test a new method for the quantitative determination of metallo- thionein (MT), in order to determine the level of exposure to heavy metals. For MT preconcentration, the solid phase extraction (SPE) method with covalent affinity chromatography with thiol-disulphide interchange (CAC-TDI) gel was applied. In experiment Cd-thionein (Cd-Th) obtained from rats exposed to cadmium salt was used. Protein concentration was determined by indirect method based on metal analysis, bonded with MT protein by atomic absorption spectrometry (AAS). The results showed satisfactory correlation between Cd-Th concentration and the level of exposition for heavy metals.

9

New ketoimine sorbents in solid phase extraction of HPLC analysis of bisphenol A and other 'endocrine disrupting' residues in drinking water

63%

Szymanski A. , Rykowska I. , Wasiak W.

Polish Journal of Environmental Studies

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2006

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tom 15

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nr 3

EN

Our study was undertaken to compare the behaviour and properties of two new ketoimine sorbents with a commercial sorbent C-18. The sorbents were used to concentrate the endocrine-disrupting compounds (EDCs) in the water, by the use at solid phase extraction (SPE). EDCs were analyzed by high performance liquid chromatography (HPLC) coupled to UV detection. The residues of bisphenol A, bisphenol A diglycidyl ether, bisphenol F and bisphenol F diglycidyl ether in the water having contact with polycarbonate plastic have been determined. The applicable concentration range was 0.5 to 100 µg/l in water samples. Detection limits were of about 0.20 µg/l for BPA and BPF, and 0.50 µg/l for diglycidyl ether derivatives. The recovery of bisphenol A introduced into water ranged from 93.3% to 97.0%, of BPF from 91.6% to 95.9%, of BADGE from 82.0% to 86.4%, and of BFDGE from 79.7 to 82.5%. The proposed method is simple and sensitive, and thus well suited for analysis of ECDs in the water.

10

Combined SPE and HPTLC as a screening assay of urinary cotinine from male adolescents exposed to environmental tobacco smoke

63%

Bazylak G. , Brozik H. , Sabanty W.

Polish Journal of Environmental Studies

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2000

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tom 09

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nr 2

EN

Cotinine, as the main metabolite of nicotine, has been determined in urine using solid-phase extraction and the high-performance thin-layer chromatographic (SPE-HPTLC) method. The urine samples were collected from a group of 35 male adolescents which were moderate or significantly exposed to home environmental tobacco smoke (ETS). l-methyl-2-pyrrolidinone was used as the internal standard in the proposed screening procedure. The thin-layer chromatograms were evaluated densitometrically after visualization of cotinine spots with ninhydrin and cadmium acetate solution. The described SPE-HPTLC procedure indicated good selectivity, sensitivity and reproducibility, enabling reliable verification of interview collected questionnaire data in families exhibiting a diversified level of ETS. The results of cotinine measurements by the proposed method were applied for assessment of hazards from home ETS on the health status of elementary schoolboys, especially an increased risk for infectious respiratory tract diseases and exercise-induced bronchospasm.

11

HPTLC assisted prediction of solid phase extraction conditions for isolation of phospholipides, triglycerides and unesterified fatty acids from biological samples

63%

Bazylak G.

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tom 04

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nr 3-4

12

Determination of aflatoxin M1 contamination levels in milk and milk products by HPLC-FLD with post – column derivatization®

51%

Polak-Śliwińska M.

Postępy Techniki Przetwórstwa Spożywczego

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2020

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tom nr 2

110--116

EN

In the present study, 34 samples of pasteurised, ultra-high-temperature (UHT) treated milk and milk products (cheese, yoghurt and baby foods) in the city of Olsztyn, Poland, were analysed for aflatoxin M1 (AFM1). All samples were cleaned up using immunoaffinity column according to Romer Labs®procedure with minor modification. The Aflatoxin M1 levels were investigated by high performance liquid chromatography with a fluorescence detection (LC-FLD) and post - column derivatization following sample clean-up using AflaStar™ M1immunoaffinity columns (Romer Labs®, Inc., America). The mean recovery of the method was 95 %. The standard curve was linear in the range of 0.01 – 0.25 μg/Lwith correlation coefficient of 0.9998. The limit of detection was 0.01 μg/L. Results showed 27 (79.4%) positive samples for AFM1 at levels of 0.010-0.053 μg/L, which were below the tolerance limit of 0.500 μg/L as adopted for AFM1 in this products by EU regulations. Mean levels of AFM1 in pasteurized and UHT milk were 0.022±0,006 μg/L and 0.030±0,002 μg/L, respectively. However, only one sample among milk samples was contaminated at a level above the maximum permissible limit (0.050 μg/L) accepted by European Union and Poland for aflatoxin M1 and six of seven samples of baby food were contaminated at a level above the maximum permissible limit (0.025 μg/L). It is concluded that the incidence of AFM1 in milk traded in Olsztyn is high, but at levels that probably leads to a non-significant human exposure to AFM1 by consumption of milk. Experimental results show that, in comparison to milk samples, AFM1 contamination level was higher in samples of baby food. These data suggest that AFM1 concentration in milk could be good predictor of its fate in milk products, especially for infants and babies. The results of this study imply that more emphasis should be given to the routine AFM1inspection of milk and milk products in Poland. Furthermore, both farmers and dairy companies should be informed on the importance of AFM1, and the consequences of the presence of the aflatoxin in dairy products.

PL

W niniejszej pracy analizie pod kątem zawartości aflatoksyny M1 (AFM1) poddano 34 próbki pasteryzowanego mleka po obróbce w ultra wysokiej temperaturze (UHT) i produktów mlecznych (ser, jogurt i żywność dla niemowląt) zakupionych w mieście Olsztyn, w Polsce. Wszystkie próbki oczyszczono przy użyciu kolumn immunoafinitywnych zgodnie z procedurą Romer Labs® z niewielkimi modyfikacjami. Poziomy aflatoksyny M1 analizowano metodą wysokosprawnej chromatografii cieczowej z detekcją fluorescencyjną (LC-FLD) z deprywatyzacją pokolumnową po oczyszczeniu próbki przy użyciu kolumn immunoafinitywnych AflaStar ™ M1 (Romer Labs®, Inc., Ameryka). Średni odzysk metody wyniósł 95%. Krzywa standardowa była liniowa w zakresie 0,01–0,25 μg/L ze współczynnikiem korelacji R2 0,9998. Granica wykrywalności wynosiła 0,01 μg/L. Wyniki pokazały 27 (79,4%) pozytywnych próbek AFM1 na poziomach 0,010-0,053 μg / l, które były po-niżej granicy tolerancji 0,500 μg/L, przyjętej dla AFM1 w tych produktach w przepisach UE. Średnie poziomy AFM1 w mleku pasteryzowanym i UHT wynosiły odpowiednio 0,022 ± 0,006 μg/L i 0,030 ± 0,002 μg/L. Jednak tylko jedna próbka wśród próbek mleka była zanieczyszczona na poziomie powyżej maksymalnego dopuszczalnego limitu (0,050 μg/L) przyjętego przez Unię Europejską i Polskę dla aflatoksyny M1, a sześć z siedmiu próbek żywności dla niemowląt było zanieczyszczonych na poziomie powyżej maksymalnego dopuszczalnego limitu (0,025 μg / l). Stwierdzono, że częstość występowania AFM1 w mleku będącym przedmiotem obrotu w Olsztynie jest wysoka, ale na poziomach, które prawdopodobnie prowadzą do nieistotnego narażenia ludzi na AFM1 w wyniku spożycia mleka. Wyniki eksperymentalne wskazują, że w porównaniu z próbkami mleka poziom zanieczyszczenia AFM1 był wyższy w próbkach żywności dla niemowląt. Dane te sugerują, że stężenie AFM1 w mleku może być dobrym wskaźnikiem jego losów w produktach mlecznych, zwłaszcza dla niemowląt i małych dzieci. Wyniki tego badania sugerują, że należy położyć większy nacisk na rutynową kontrolę AFM1 mleka i przetworów mlecznych w Polsce. Ponadto zarówno rolnicy, jak i firmy mleczarskie powinni być informowani o znaczeniu AFM1 i konsekwencjach obecności aflatoksyny w produktach mlecznych.

13

Analiza zawartości pozostałości środków farmaceutycznych w wodach ściekowych

51%

Styszko K.

Laboratorium - Przegląd Ogólnopolski

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2016

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tom nr 7-8

12--21

PL

Analityka pozostałości farmaceutyków w wodach ściekowych opiera się przede wszystkim na zastosowaniu technik chromatograficznych sprzężonych ze spektrometrią mas. Obok pobierania, przechowywania i transportu próbek do analizy niezwykle istotny jest etap dalszego przygotowania, który ma na celu w jak największym stopniu uproszczenie matrycy i wzbogacenie analitów. Pozostaje on szczególnym wyzwaniem w przypadku takich próbek jak ścieki surowe. W pracy omówiono problem występowania pozostałości farmaceutyków w środowisku, źródła ich emisji, obecność w oczyszczalniach ścieków oraz analitykę z uwzględnieniem technik chromatograficznych sprzężonych ze spektrometrią mas.

EN

Chromatographic techniques combined with mass spectrometry are the most popular methods for the identification and quantitative analysis of pharmaceutical residues in environmental samples. Besides collection, storing and transportation, the extraction step is the most important part of the whole sample preparation procedure. In the paper, the problem of the presence of pharmaceutical residues in the environment, the sources of their emission, their presence in wastewater treatment plants, as well as analytical methods including chromatographic techniques with mass spectrometry have been presented.

14

Use of solid phase extraction and thin-layer chromatography in screening procedure for quantitation of ethanolamine and its methylated forms in rat liver cells

51%

Bazylak G.

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tom 03

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nr 3-4

15

Wielopozostałościowa metoda oznaczania herbicydów z grupy chloroacetanilidów

38%

Kucharski M. , Sadowski J. , Michnik A.

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nr 4

EN

The aim of investigation was to elaborate an analytical method of determination of chloroacetanilide herbicide active substances: propachlor, dimethachlor, alachlor, propisochlor, metolachlor and metazachlor in soil, plant and water samples. The analytical procedure consist of three elementary processes: extraction of analyzed substances from matrix, cleaning of extract using SPE (Solid Phase Extraction) column with C18 active solid and final determination using gas chromatography with ECD detection. The detection limit (LOD) of all tested chloroacetanilide compounds was 0.0002 mg/kg (for soil and plant samples) and 0.00002 mg/kg for water samples. The range of fortified recoveries of the method was 90–98%.

16

Analiza GC-MS fazy nadpowierzchniowej ekstraktu z suszonego brokulu [Brassica oleracea L. var. italica] otrzymanego przy wykorzystaniu ditlenku wegla w stanie podkrytycznym

32%

Tambor K. , Rutkowska J. , Perajski S.

Bromatologia i Chemia Toksykologiczna

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2009

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tom 42

|

nr 3

282-287

17

Wykrywanie i oznaczanie pozostalosci florfenikolu i tiamfenikolu w tkankach jadalnych zwierzat metoda elektroforezy kapilarnej

32%

Kowalski P. , Plenis A. , Oledzka I.

Bromatologia i Chemia Toksykologiczna

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2009

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tom 42

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nr 3

569-573