Wyniki wyszukiwania

1

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

|

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.

2

Determination of tocopherols by packed column supercritical fluid chromatography [SFC]

88%

Buskov S., Jorgensen S. S., Sorensen H.

Polish Journal of Food and Nutrition Sciences

|

1999

|

tom 08

|

nr 3

Supercritical fluid chromatographic (SFC) separations of a-tocopheryl acetate, α-, ß-, y- and -tocopherol have been achieved on a Spherisorb S3 ODS2 column in about 15 minutes. Separation efficiency of this method has been optimised with respect to the effect of pressure, percent of methanol in the mobile phase, temperature and flow rate, resulting in theoretical plate numbers (N) varying from 63000 to 90000 per metre. Linear correlations have been found between log k' (retention factor) and fluid density for all of the tested compounds, and a van't Hoff plot yielded linear correlation between log k' and T-1 at constant mobile phase density. Linearity and repeatability were found to be acceptable with detection limits from approximately 20 ng for α-, ß-, y- and ő-tocopherol to 10 ng for a-tocopheryl acetate at a signal to noise ratio = 3. Results obtained by use of the developed SFC method to determination of tocopherols in plant oils obtained by SFE (supercritical fluid extraction) and by aqueous enzymatic processing are presented.

3

Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik

Characteristics of biologically-active substances of amaranth oil obtained by various techniques

75%

Czaplicki S., Ogrodowska D., Zadernowski R., Derewiaka D.

Polish Journal of Food and Nutrition Sciences

|

2012

|

tom 62

|

nr 4

Amaranth seeds and their main product amaranth oil are a rich source of bioactive substances. The non-saponifi able substances which accompany lipids include: squalene, tocopherols, sterols and others. The aim of the study was to compare the content of squalene, tocopherols and phytosterols in amaranth oils obtained by various techniques. The oil was extracted from seeds (Amaranthus cruentus) with the use of supercritical fl uid extraction (SFE), extraction with a chloroform/methanol mixture and expeller pressing. Contents of squalene and tocopherols were determined with high performance liquid chromatography (HPLC) method. The content of sterols in oils was determined by gas chromatography coupled with mass spectrometry (GC-MS). The highest squalene content was found for the oil obtained as a result of supercritical CO2 extraction (6.95 g/100 g of oil). A lower content of squalene was noted in the oil extracted with organic solvents and in cold-pressed oil – 6.00 and 5.74 g/100 g of oil, respectively. The amaranth oils were characterised by a signifi cant content of tocopherols. The oil obtained as a result of fl uid extraction was characterised by the highest content of tocopherols (131.7 mg/100 g of oil). A dominating homologue (40%) was β-tocopherol. Also the same sample was characterised by the highest content of sterols (2.49 g/100 g of oil). In all samples the predominating sterol was sum of α-spinasterol and sitosterol, which accounted for 45%, 56% and 53% of total analysed sterols for the oil obtained from SFE, from extraction with solvents and from cold pressing, respectively.

4

Supercritical fluids

75%

Askin R., Otles S.

Acta Scientiarum Polonorum. Technologia Alimentaria

|

2005

|

tom 04

|

nr 1

3-16

This study includes information concerning supercritical fluids. Beginning from the general description of the supercritical fluids, their historical background with physico-chemical properties is given. Special properties with the aid of which supercritical characteristics are obtained are attempted to be explained. Also, supercritical C02 (SCC02), as a solvent for extraction related to the advantages of using such a solvent carrying supercritical properties, is discussed. In order to understand the mechanism of supercritical fluid extraction (SFE), the modelling concept of supercritical fluids (SCFs) and the criteria for various separation techniques are redefined.

5

Study of chlorothalonil uptake in selected plant materials

75%

Zebrowski W., Ligor T., Buszewski B.

Polish Journal of Environmental Studies

|

2008

|

tom 17

|

nr 3

321-326

The objective of this work was to create a sorption model of different pesticides in plant material. The above-quoted model includes graphic curves describing the pesticide’s behaviour in time (concentration level) depending on the place of sorption. Apart from curves the model also includes mathematical equations that allow us to predict the concentration of a pesticide in time function. The model has been developed based on research data obtained in a special experimental device. This article accounts for the transportation model of chosen xenobiotics in plants. Chlorothalonil were used as a model pesticide. Chlorothalonil is a nonsystemic fungicide that has been used to control disease of many fruits, vegetables, and other agricultural crops. As a method of sample preparation supercritical fluid extraction was used. Gas chromatography with mass spectrometry was used for qualitative and quantitative analysis. The detection limit (LOD) of chlorothalonil was on level 0.01 µg/g. and the limit of quantification (LOQ) was level on 0.03 µg/g.

6

The effects of heavy metals, content of nutrients and inoculation with mycorrhizal fungi on the level of terpenoids in roots of Pinus sylvestris seedlings

63%

Werner A., Napierala-Filipiak A., Mardarowicz M., Gawdzik J.

Acta Physiologiae Plantarum

|

2004

|

tom 26

|

nr 2

7

Quantitative extraction of oil from plant material with supercritical carbon dioxide

51%

Buskov S., Sorensen H., Sorensen J. C., Sorensen S.

Polish Journal of Food and Nutrition Sciences

|

1997

|

tom 06

|

nr 3

Supercritical fluid extraction (SFE) both with CO2 and CO2/hexane has been developed as a method of analysis for lipids in cruciferous oilseed, rapeseed products and lupin. The SFE procedure used for quantitative determination of oil was compared to traditional Soxhlet oil extraction. The quantitative values obtained with SFE were equal to those obtained with the Soxhlet procedure with respect to oil and fat contents. The oil obtained by SFE had a much lower phosphorus content (below 14 mg/kg compared to 200-530 mg/kg in oil obtained with Soxhlet). When adding hexane to the supercritical fluid in concentrations varying from 50 to 150 mL/L CO2, the solubility of oil in the fluid could be raised up to 600%, from about 30 mg/g without addition of modifier to nearly 200 mg/g when using continuous addition of 150 mL hexane/ L CO2. The phosphorus content was still lower than in oil from Soxhlet (20-64 mg/kg). Therefore, extraction of oil with SFE opens the possibility for selective removal of oil before separate extraction and determination of amphiphilic compounds, e.g. phospholipids. The carotenoid and chlorophyl content in different oils from SFE and Soxhlet were evaluated by UV-VIS determinations. The presence of other amphiphilic compounds was verified and sinapic acid was found to be a quantitatively dominating phenolic compound.

8

Characterisation of dietary fibre-associated constituents based on supercritical fluid extraction

45%

Andersen K. E., Bjergegaard C., Sorensen H.

Polish Journal of Food and Nutrition Sciences

|

1998

|

tom 07

|

nr 4

Ograniczanie wyników

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

Determination of tocopherols by packed column supercritical fluid chromatography [SFC]

Characteristics of biologically-active substances of amaranth oil obtained by various techniques

Supercritical fluids

Study of chlorothalonil uptake in selected plant materials

The effects of heavy metals, content of nutrients and inoculation with mycorrhizal fungi on the level of terpenoids in roots of Pinus sylvestris seedlings

Quantitative extraction of oil from plant material with supercritical carbon dioxide

Characterisation of dietary fibre-associated constituents based on supercritical fluid extraction