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

100%
Cichy A., Dratwa-Chalupnik A., Medenska W., Ozgo M.
Animal Science and Genetics
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2022
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tom 18
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nr 3
2

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
|
1996
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tom 05
|
nr 6
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.
3

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
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.
4

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
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.
5

Green aspects of sample preparation - a need for solvent reduction

75%
Curylo J., Wardencki W., Namiesnik J.
Polish Journal of Environmental Studies
|
2007
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tom 16
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nr 1
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.
6

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
|
nr 4
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.
7

Two methods of sample preparation for analysis of non-ortho and mono-ortho PCB congeners in the muscles of selected fish species

63%
Witczak A., Chlewinska M.
Acta Ichthyologica et Piscatoria
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2008
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tom 38
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nr 1
Background. Polychlorinated biphenyls (PCBs) are persistent organic pollutants widespread in the environment. Their ability to accumulate in living organisms leads to food contamination, which is the main route of human exposure to PCBs. During analytical procedure of PCB residue determination, losses of these compounds may occur, which contribute to obtaining underestimated analytical results. Adequate analytical method of chlorobiphenyls determination should be applied to avoid the losses and obtain high recoveries and furthermore to enable accurate estimation of the risk of consuming contaminated food. Especially fish, due to the high bioaccumulation, may contain considerable amounts of these compounds. The aim of this study was to determine if the method of sample preparation influences the recovery of non-ortho (PCB 77, 81, 126, 169) and mono-ortho (PCB 105, 114, 156, 157) PCB congeners in selected fish species. Materials and Methods. To prepare samples for chromatographic determination (HP 6890/5973 GC MS) two methods were applied. Fish muscle tissues were dried by rubbing in a mortar with anhydrous sodium sulphate or freeze dried (lyophilised) (LyoLAB 3000). The samples were fortified with a known amount of internal standard (decachlorobiphenyl), and some were additionally fortified with the standard solution of analysed PCB congeners. Results. nternal standard recoveries ranged from 57.61 ± 1.21% to 88.76 ± 4.03% in freeze-dried samples, and from 63.81 ± 5.11% to 97.50 ± 6.14% in samples rubbed with anhydrous sodium sulphate. Following lyophilisation, recoveries of analysed PCB congeners varied from 68.88 ± 11.74% for PCB 157 to 79.18 ± 12.33% for PCB 114. In the samples rubbed with anhydrous sodium sulphate the lowest recovery was determined for PCB 77 (72.40 ± 12.34%), the highest being typical for PCB 156 (83.47 ± 12.86%). Following lyophilisation, toxic equivalents (TEQs) for the examined fish species ranged from 0.0050 ng-TEQ·g-1 dry weight in salmon to 0.0299 ng-TEQ·g-1 dry weight in mackerel. Following rubbing with anhydrous sodium sulphate the highest toxic equivalent (0.0326 ng-TEQ·g-1 dry weight) was calculated for mackerel, and the lowest for salmon (0.0055 ng-TEQ·g-1 dry weight). Conclusion. The research has demonstrated that in most cases the results obtained with both methods have not differed significantly (P < 0.05), although freeze drying resulted in slightly higher losses of PCB congeners. Despite of smaller recoveries, freeze drying can be applied because of solvent saving and easier sample preparation.
8

Organic pollutants of soils and sediments. Methods of sample preparation and isolation-preconcentration of analytes prior to their final determination

63%
Namiesnik J., Zygmunt B., Biziuk M., Wiergowski M., Torres L.
Polish Journal of Environmental Studies
|
1996
|
tom 05
|
nr 1
This work presents basic information on preparing previously handled samples of soils and sediments in order to determine low concentrations of different organic contaminants (Volatile Organic Compounds (VOCs), Polychlorinated Biphenyls (PCBs), Polychlorinated Aromatic Hydrocarbons (PAHs), pesticides, and Polychlorinated Dibenzo-p-dioxins and Polychlorinated Dibenzofurans (PCDD/F), etc.). Solid environmental samples such as soils and sediments are subjected to different pretreatment processes, including: - isolation and preconcentration of analytes from the sample matrix, - clean-up of extracts, and - preconcentration of analytes from a secondary matrix (solvent, gas). The literature described here is closely related to these analytical operations. A separate chapter focuses on the application of Supercritical Fluid Extraction (SFE) in analytics of organic pollutants in solid environmental matrices. Today SFE is becoming the most often used technique in these areas.
9

Atmospheric precipitation sampling for analysis

63%
Grynkiewicz M., Polkowska Z., Zygmunt B., Namiesnik J.
Polish Journal of Environmental Studies
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2003
|
tom 12
|
nr 2
This paper reviews collectors for atmospheric precipitation (rain, fog, and run-off water). Collection systems of a different degree of automation (from simple designs to highly automated costly collectors) are presented. In many papers on collecting atmospheric precipitation neither sampling procedures nor locations of sampling sites are given, although this information is necessary for producing correct and comparable results of physical and chemical analyses.
10

Optimization of a measurement of flavonol aglycons in some medicinal plants by SPE-RP-HPLC method. Part 2. Choice of the way of sample preparation and purification

63%
Nowak R.
Herba Polonica
|
2003
|
tom 49
|
nr 3-4
The aim of this examination was optimization of flavonols' detection method in plant's extracts. The leaves of Rosa canina L. and Rosa damascena Mill, were chosen as the experi­mental material, due to their rich content of flavonols. In the study, optimization and comparison of extraction, hydrolysis and purification processes of samples predesti­nated to HPLC analysis of flavonol aglycones were performed. The most optimal method to detect flavonols in examined material was their direct hydrolysis with 1.2 N HCL dur­ing 1 h connected with its extraction with 50% methanol and then purification of the sample by SPE before HPLC examination. The comparison and evaluation of two elaborated methods of hydrolyzate purification from neutral compounds, which are liquid-liquid extraction (LLE) with ethyl acetate and solid phase extraction (SPE) in RP-18 microcolumns, were carried out. 78% recovery of standard quercetin during LLE and 98.8% recovery of standard quercetin during filtering and elution of hydrolyzate with methanol through octadecyl microcolumns in SPE method were observed. These results showed that SPE is better then LLE during superior sample purification procedure.
11

An investigation of the formation of taste and odour contaminants in surface water using the headspace SPME-GC-MS method

63%
Ligor M., Buszewski B.
Polish Journal of Environmental Studies
|
2006
|
tom 15
|
nr 3
The aim of this study was to optimize of a method for determining of compounds which are responsible for the earthy/musty odour in surface water. Among taste and odour contaminants the following compounds are mentioned: (+/-)-geosmin, 2-methylisoborneol, 2,4,6-trichoroanisole, 2-isopropyl-3-methoxypyrazine and 2-isobutyl-3-methoxypyrazine. Some experiments were performed to examine the extraction conditions such as fiber exposure time, temperature of extraction and salt addition. Various SPME fibers such as PDMS, CAR/PDMS and PDMS/DVB coatings were used for the isolation of tested compounds from water samples. As tested, compounds 2-methylisoborneol, 2-isopropyl-3-methoxypyrazine and 2-isobutyl-3-methoxypyrazine were used. After SPME optimization, real surface water samples were examined using the SPME-GC/MS method. Based on preliminary experiments the qualitative and quantitative analyses for the determination of (+/-)-geosmin, 2-methylisoborneol and 2,4,6-trichloroanisole were performed. The regression coefficients for calibration curves for examined compounds are R²≥0.990. This shows that the used method is linear in the examined concentration range (from 20.32 to 168.00 ng/L). one of the reasons for the formation of taste and odour contaminants can be surface water pollution. The changes of water conditions such as temperature, pH and conductivity were examined. And, for the test of periodical changes of geosmin concentration in surface water samples, the experiments were performed in various seasons.
12

Assessment of selected heavy metal contents in medicinal plants, tea leaves and chocolate using atomic absorption spectrometry

63%
Srogi K.
Acta Toxicologica
|
2006
|
tom 14
|
nr 1-2
13

Isolation, determination and sorption modelling of xenobiotics in plant materials

51%
Michel M., Buszewski B.
Polish Journal of Environmental Studies
|
2008
|
tom 17
|
nr 3
305-319
Crop models use mathematical equations to simulate the physical and chemical processes that generally control the uptake, translocation, and sorption of xenobiotics in all part of plants. Each compartment is anatomically characterized and described by a series of mathematical equations. Sample preparation, such as liquid extraction methods and solid-phase-based methods are presented. Analysis of xenobiotics are generally carried out by gas chromatography (GC) or liquid chromatography (LC) coupled to different detectors, especially to mass spectrometers (MSs) and hyphenated techniques that have become extremely developed in recent years. As an example the wheat plant, as a model to describe xenobiotic uptake by roots and sorption of xenobiotic in grain, is applied.
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