Wyniki wyszukiwania - Biblioteka Nauki

1

Methodology to develop liquid chromatographic fingerprints for the quality control of herbal medicines

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Dejaegher B. , Alaerts G. , Matthijs N.

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2010

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tom Vol. 22, no. 2

237--258

EN

A liquid chromatographic fingerprinting methodology has been established for identification and quality control of traditional herbal medicines. The methodology was developed from four case studies. Samples of Herba Artemisia annua, Herba Artemisia scoparia, Rhizoma Ligusticum chuanxiong (also called Rhizoma chuanxiong ), and Rhizoma Ligusticum jeholense (also called Rhizoma ligustici ) were investigated. In each case study, sample preparation and chromatographic conditions (column, organic modifier, column temperature, detection wavelength, and mechanism) were varied to obtain good fingerprints, i.e. with the maximum number of peaks. Further optimization was then performed either by reducing the analysis time or increasing efficiency. The case studies led to the development of a general methodology consisting of sample preparation and HPLC fingerprint development. The fingerprints obtained with the developed methodology were then successfully used to distinguish between the two Artemisia species and between the two Ligusticum species. The methodology also was used to obtain fingerprints for a large number of different Vietnamese Mallotus species, and for Citri reticulatae pericarpium samples collected in different regions of China.

2

Analiza sensoryczna w zapewnieniu jakości żywności

100%

Baryłko-Piekielna N.

Przemysł Spożywczy

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1998

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tom T. 52, nr 12

25-28

PL

Wśród aktualnych metod i systemów zapewnienia jakości żywności ważne i unikalne miejsce zajmuje analiza sensoryczna. W praktyce nie wszystkie oceny jakości sensorycznej produktów stosowane w przemyśle spełniają warunki współczesnej definicji analizy sensorycznej, opartej na podstawowej znajomości zasad funkcjonowania sensorycznego "aparatu pomiarowego". Jako dział analizy żywności, analiza sensoryczna dysponuje wieloma metodami, o ściśle wystandaryzowanej procedurze przygotowania i prezentacji próbek oraz opracowania wyników. Standaryzację zapewniają normy metodyczne ISO, przyjmowane obecnie jako PN. Ważnym elementem w rozpowszechnieniu zastosowania analizy sensorycznej w zapewnieniu jakości jest wykształcenie specjalistów; przedstawiono jakie wymagania ma on spełniać oraz możliwości uzyskania odpowiednich kwalifikacji w tej dziedzinie. Zainteresowanie producentów żywności zastosowaniem analizy sensorycznej w ostatnich latach rośnie.

EN

Among contemporary methods and systems of food quality assurance, the sensory analysis occupies important and unique position. Although the term is used, not all kinds of sensory quality evaluation fulfil requirements given in the definition of sensory analysis, founded on the basic knowledge of sensory apparatus functioning. As a section of food analysis, the sensory analysis uses many methods, strictly standardised in regard to the sample preparation and presentation as well as the data (results) processing. ISO methodological standards of sensory analysis are now being adapted as the Polish Standards. An important factor in the spreading out industrial application of sensory analysis in the quality assurance is specialists' education and training; the quality requirements for such specialists (panel leaders) as well as possibilities to get qualified in this area have been discussed. In recent years the food producer interest in practical application of sensory analysis is growing remarkably.

3

Strategies to increase selectivity of analytical methods for As, Cr and Se speciation in biological samples: A review

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Carvalho D. C. , Coelho N. M. M. , Melo Coelho L. , Borges S. S. S. , Neri T. S. , Alves V. N.

Sample Preparation

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2014

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tom 2

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nr 1

EN

This review provides an overview and discusses different analytical strategies that minimize or eliminate the preparation of samples for speciation of organic and inorganic species of As, Cr and Se in samples of biological interest. These metals are important for the human body and the presence of various chemical forms of metals determines its essentiality and toxicity, thus speciation comes as an important tool for the study of biological samples. However, speciation requires a reduction in the steps of sample preparation, allowing a sample investigation in its most native form in order to reduce the changes in chemical species. The strategies proposed for speciation of these metals include: solid phase extraction, point cloud extraction, suspension and direct analysis. Selected methods proposed for the speciation of organic and inorganic species of As, Cr and Se were reviewed including their main figures of merit, advantages and disadvantages

4

Solid Phase Extraction for Evaluation of Occupational Exposure to Pb (II) Using XAD-4 Sorbent Prior to Atomic Absorption Spectroscopy

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Shahtaheri S. J. , Khadem M. , Golbabaei F. , Rahimi-Froushan A. , Ganjali M. R. , Norouzi P.

International Journal of Occupational Safety and Ergonomics

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2007

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tom Vol. 13, No. 2

137--145

EN

Lead is an important constituent widely used in different industrial processes. For evaluation of workers’ exposure to trace toxic metal of Pb (II), solid-phase extraction (SPE) was optimized. SPE using mini columns filled with XAD-4 resin was developed with regard to sample pH, ligand concentration, loading flow rate, elution solvent, sample volume, elution volume, the amount of resins, and sample matrix interferences. Lead ions were retained on a solid sorbent and then eluted, followed by a simple determination of analytes with flame atomic absorption spectrometery. The obtained recoveries of metal ions were greater than 92%. This method was validated with 3 different pools of spiked urine samples; it showed a good reproducibility over 6 consecutive days as well as 6 within-day experiments. This optimized method can be considered successful in simplifying sample preparation for a trace residue analysis of lead in different matrices when evaluating occupational and environmental exposures is required.

5

Evaluation of four procedures for preparing mare milk samples for proteomic analysis

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Cichy A. , Dratwa-Chalupnik A. , Medenska W. , Ozgo M.

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nr 3

6

Possibilities and limitations of supercritical fluid extraction [SFE] as a sample preparation technique

100%

Kot A. , Sandra P. , Kolodziejczyk A. M.

Polish Journal of Environmental Studies

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1996

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tom 05

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nr 6

EN

This review focuses on different attempts to understand the process during extraction • sing supercritical fluids and on different approaches to obtain quantitative and selective extractions. Supercritical fluid extraction is a fast technique and, unlike other methods of extraction, allows several sample preparation steps to be incorporated within the extraction step. The authors consider the possible methods of optimisation of the SFE variables - fluid type, modifiers of the fluid, pressure (density), temperature, flow rate, sample size, analyte collection, and fixation - to help an analyst to extract the solutes of interest in a quantitative way while avoiding or minimising co-extraction of other matrix components.

7

Sample Preparation for Determination of Biological Thiols by Liquid Chromatography and Electromigration Techniques

88%

Bald E. , Department o f Environmental Chemistry U. o. L.

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PL

Wydrukowano z dostarczonych Wydawnictwu UŁ gotowych materiałów

EN

Majority of the bioanalytical or environmental methods do not use just one chromatografie or electrophoretic step, but rather involve several sample pretreatment steps which simplfy the matrix, and often preconcentrate and chemically modify the analytes. This work surveys typical procedures for sample preparation for most commonly analyzed biofluids with particular emphasis placed on chemical derivatization of sulfur amino acids for their determination by liquid phase separation techniques. Recent author's laboratory contribution to the development of sample preparation procedures is merked.

8

Pobieranie i przygotowanie próbek produkcyjnych węgla według PN-90/G-04502 w świetle postanowień starych i nowych norm międzynarodowych

75%

Pyka I.

Zeszyty Naukowe. Górnictwo / Politechnika Śląska

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2005

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tom z. 266

195-204

PL

Dokonano krytycznej analizy postanowień PN-90/G-04502, Węgiel kamienny i brunatny. Metody pobierania i przygotowania próbek do badań laboratoryjnych. Postanowienia te skonfrontowano z postanowieniami ISO 1988:1975, z którą polska norma powinna być równoważna (zgodna) oraz z postanowieniami najnowszych dokumentów normalizacyjnych Międzynarodowej Organizacji Normalizacyjnej (ISO). Są to ISO 13909, w której ustalono zasady mechanicznego pobierania próbek węgla i koksu, oraz projekt normy międzynarodowej ISO/DIS 18283, w której mają być ustalone zasady ręcznego pobierania próbek węgla i koksu.

EN

Polish Standard PN-90/G-04502 dealing with the hard and brown coal sampling and sample preparation is critically analysed. It is compared with ISO 1988:1975 and the newest international standard documents on coal sampling and sample preparation. PN 90/G-04502 is to be equivalent to old standard ISO 1988:1975. The newest international standard documents are as follow: ISO 13909 (dealing with mechanical coal and coke sampling) and ISO/DIS 18283 (the draft of the standard dealing with manual method of coal and coke sampling).

9

Sample Preparation Followed by High Performance Liquid Chromatographic (HPLC) Analysis for Monitoring Muconic Acid as a Biomarker of Occupational Exposure to Benzene

75%

Shahtaheri S. J. , Ghamari F. , Golbabaei F. , Rahimi-Froushani A. , Abdollahi M.

International Journal of Occupational Safety and Ergonomics

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2005

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tom Vol. 11, No. 4

377--388

EN

Factors affecting solid phase extraction (SPE) of trans,trans-muconic acid (ttMA), as a benzene biomarker, including sample pH, sample concentration, sample volume, sample flow rate, washing solvent, elution solvent, and type of sorbent were evaluated. Extracted samples were determined by HPLC-UV (high performance liquid chromatography-ultraviolet). The analytical column was C18, UV wave length was 259 nm, and the mobile phase was H2O/methanol/acetic acid run at flow rate of 1 ml/min. A strong anion exchange silica cartridge was found successful in simplifying SPE. There was a significant difference between recoveries of ttMA when different factors were used (p < .001). An optimum recovery was obtained when sample pH was adjusted at 7. There was no significant difference when different sample concentrations were used (p > .05). The optimized method was then validated with 3 different pools of samples showing good reproducibility over 6 consecutive days and 6 within-day experiments.

10

Novel selective sorbents for solid-phase extraction

75%

Pyrzyńska K.

Chemia Analityczna

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2003

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tom Vol. 48, No. 5

781-795

EN

Solid-phase extraction (SPE) is an attractive approach towards preparation of many kind of samples prior to their chromatographic analysis and highly selective sorbents are required for this purpose. The objective of this review is to provide updated information about the most important features of the new SPE materials, their interaction mode and potential applications for the environmental, food and biological samples. New selective phases such as restricted access materials, immunosorbents and molecularly imprinted polymers are described. Selected examples illustrate the potential of these sorbents.

PL

Zastosowanie techniki ekstrakcji do fazy stałej to tani i wygodny sposób przygotowania próbek środowiskowych i biologicznych przed ich analizą metodami chromatograficznymi. W pracy przedstawiono ostatnie doniesienia literaturowe dotyczące zastosowania nowych, selektywnych sorbentów takich jak polimery „drukowane" (molekularnego rozpoznania), immunosorbenty i sorbenty ograniczonego dostępu, do wyodrębnienia i zatężania różnego rodzaju analitów. Wybrane przykłady ilustrują możliwości tych sorbentów w analizie próbek naturalnych.

11

An improved method for obtaining small pressed powder pellets for the analysis by XRF

75%

Angelo J. D. , Strasser E. , Marchevsky E. , Perino E.

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tom Vol. 47, No. 6

913-924

12

Miniaturized sample preparation based on carbon nanostructures

75%

Cárdenas S.

Sample Preparation

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2014

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tom 2

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nr 1

EN

The evolution of analytical methodologies has been driven by the objective to reduce the complexity of sample treatment while increasing the efficiency of the overall analytical process. For this reason, the analytical chemist takes into consideration advances in other scientific areas and systematically evaluates the potential influence that such discoveries might have on its own discipline. This is the present situation with nanostructured materials, which have already been recognized as a revolution in many scientific and technological fields, including analytical chemistry. Carbon nanoparticles have been a cornerstone in the advance of miniaturization of analytical processes. This review article considers the contribution of four reference carbon nanoparticles: nanotubes, graphene, nanohorns/ cones and fullerenes, in the context of miniaturized sample treatment, where their outstanding sorbent properties are by far the most exploited in (micro) solid phase extraction.

13

Automatyzacja i robotyzacja metod przygotowania próbek do analiz chemicznych

75%

Rogala P. , Bielecki M. , Witkiewicz Z.

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2019

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tom T. 24, nr 2

115--121

PL

Przedmiotem artykułu jest przegląd metod przygotowania próbek do analizy chemicznej, w których proces przygotowania próbki jest zautomatyzowany i sprzężony z przyrządem pomiarowym. Zaprezentowano przykłady metod przygotowania próbek ciekłych i stałych z elementami automatyzacji i robotyzacji tego procesu.

EN

The subject of the article is a review of method samples preparation for chemical analysis, in which the sample preparation process is automated and coupled to the measuring instrument. Examples of methods for preparing liquid and solid samples with elements of automation and robotization of this process are presented.

14

Application of ICP-OES spectrometry for determination of high concentrations of silicon in cast iron and steel

75%

Knapik P.

Journal of Metallic Materials

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2021

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tom Vol. 73, no. 3

29--32

EN

The study investigates the possibility of applying induced plasma atomic emission spectrometry (ICP-OES) to determine silicon content exceeding 0.5% in iron-based samples. ICP-OES spectrometry requires liquid samples. Solid samples must be dissolved prior to the analysis. Dissolution of some types of steel requires strongly oxidising mixtures of inorganic acids. In such conditions, higher silicon contents tend to form insoluble oxides. Silicon oxides, in the form of amorphous sediment, precipitate on the bottom and walls of laboratory vessels. As a result, silicon determinations are strongly underestimated. The article presents the preparation of iron matrix based solutions for the determination of silicon-high concentrations using ICP-OES spectrometry.

PL

Celem pracy było zbadanie możliwości zastosowania techniki atomowej spektrometrii emisyjnej ze wzbudzeniem w plazmie indukowanej (ICP-OES), do oznaczania krzemu w zakresie stężeń przekraczających 0,5%, w próbkach na osnowie żelaza. Badanie składu chemicznego stali techniką ICP-OES wymaga przygotowania próbek w postaci roztworów. Roztworzenie niektórych gatunków stali wymaga zastosowania silnie utleniających mieszanin kwasów nieorganicznych. Warunki te, w przypadku wyższych zawartości krzemu, sprzyjają powstawaniu nierozpuszczalnego tlenku tego pierwiastka. Tlenek krzemu, w postaci amorficznego osadu, wytrąca się na dnie i ściankach naczyń laboratoryjnych. W efekcie, wyniki oznaczeń krzemu są silnie zaniżone. W artykule przedstawiono sposób przygotowania roztworów próbek na osnowie żelaza, do oznaczeń wysokich stężeń krzemu techniką ICP-OES.

15

Przygotowanie próbki podstawą sukcesu!

75%

Bars B. F. , Martinez E. , Grzeski H. N.

LAB Laboratoria, Aparatura, Badania

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2018

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tom R. 23, nr 4

6--9

16

The influence of solvent choice on the recovery of phytogenic phenolic compounds extracted from plant material

75%

Jaroszynska J.

Polish Journal of Environmental Studies

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2003

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tom 12

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nr 4

EN

Sometimes, the preparation of a plant sample to GC analysis undergoes the stage of drying plant ex-tract from the solvent, and subsequently the repeated extraction of the dry residue in a different solvent. The purpose of this procedure is to separate the studied phenolic compounds from the matrix. This paper presents the results of the research into the effect of the type of solvent used in the proceeding (methanol, water, acetone, diethyl ether or chloroform) on the size of losses in the phenolic compounds during such a procedure. It has been noted that the greatest recovery appears in cases of methanol and acetone, whereas water may be the source of considerable losses in the compounds during the preparation of the plant sample for analysis.

17

Microwave methods of sample preparation for the purposes of environmental analysis

75%

Szablewski L. , Jastrzebska A. , Buszewski B.

Polish Journal of Environmental Studies

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1997

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tom 06

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nr 5

EN

The application of microwave techniques for environmental sample preparation is described. Special attention has been given to the theoretical foundations and the possibilities of using microwave radiation in mineralization and extraction. These techniques are compared with conventional methods and examples of their application are supplied.

18

Solid phase microextraction as a method for preparing environmental samples

75%

Ligor M. , Buszewski B.

Polish Journal of Environmental Studies

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1997

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tom 06

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nr 5

EN

A new technique for sample preparation, Solid Phase Microextraction (SPME), is described. Theoretical and practical aspects and the particular possibility of using this technique in environmental analyses are discussed (application for analytical determination in different matrix). This paper will show many advantages as well as faults of SPME.

19

Green aspects of sample preparation - a need for solvent reduction

75%

Curylo J. , Wardencki W. , Namiesnik J.

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2007

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tom 16

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nr 1

EN

Growing public concern over protecting our environment obligates chemists, including analytical chemists, to change chemical activity in such a way that it will be conducted in an environmentally friendly manner. The article provides an overview of green chemistry issues relating to sample preparation techniques, concentrating especially on the green advantages of so-called solventless sample preparation. Current sample preparation techniques, fulfilling the demands of green chemistry standards, are presented, along with consideration of their features and advantages.

20

Wpływ przygotowania próbki na oznaczanie związków niepożądanych w matrycy nasion owoców jagodowych

63%

Węglarz I. , Mazurek B. , Chmiel M. , Górecka B.

Przemysł Chemiczny

|

2013

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tom T. 92, nr 5

819-823