Sökning: "supercritical"

Visar resultat 21 - 25 av 94 avhandlingar innehållade ordet supercritical.

1. 21. Analytical Supercritical Fluid Extraction of Lipid Containing Samples

   Författare :Mattias Järemo; Centrum för analys och syntes; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; SFC; extraction cell; liquid samples; fat retainers; lipids; SFE; carbon dioxide; Analytical chemistry; Analytisk kemi;

   Sammanfattning : Traditionally, sample work-up has been associated with different kinds of liquid extraction techniques involving a large consumption of hazardous solvents. There are today regulations that aims at replacement of dangerous chemicals which has created a need for new extraction techniques. LÄS MER

3. 22. On the Extraction of Essential Oils by Supercritical Carbon Dioxide and its Influence on the Mesomorphic Phase Structures

   Författare :José da Cruz Francisco; Kemiska institutionen; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Natural oils; fats and waxes technology; Naturliga oljor; fetter; vax; Kemiteknik och kemisk teknologi; Chemical technology and engineering; Livsmedelsteknik; Food and drink technology; phase behavior; soybean lecithin; monoolein; cineole; terpenes; eucalyptus; extraction; Essential oils; supercritical carbon dioxide;

   Sammanfattning : A comparison of essential oils from leaves of Eucalyptus camaldulensis Dehn. obtained by hydrodistillation (HD) and supercritical carbon dioxide (SC-CO2) extraction is presented. Selected major components of the oils showed a predominance of higher molecular weight components in the SC-CO2 extracts than in those obtained by HD. LÄS MER

4. 23. Development of Methods for Determination of Fat and Trace Constituents in Food, with Emphasis on Supercritical Fluid Extraction

   Författare :Hans Berg; Centrum för analys och syntes; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Supercritical fluid extraction; Steroids; SFE; Sample preparation; Meat; Lipid classes; Food; Fatty acid composition; Fat content; 3-butanediol; 2; Diacetyl; Acetoin; Androstenone; vitamins A and E.; Analytical chemistry; Analytisk kemi;

   Sammanfattning : Sample preparation is the most time-consuming step in an analysis. Traditional sample preparation techniques consume large amounts of organic solvents, are time-consuming and are difficult to automate. LÄS MER

5. 24. Open-tubular columns for liquid and supercritical fluid chromatography

   Författare :Karel Janák; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Analytical Chemistry; analytisk kemi;

   Sammanfattning : Methods have been developed for the preparation of narrow-bore open tubularcolumns. In this content, condensed gases (butane, chloroethane and Freon114) were used as solvents for the static coating of these columns. Adevice for filling the narrow-bore open tubular columns with solutions incondensed gases has been designed. LÄS MER

7. 25. Packed capillary columns in liquid and supercritical fluid chromatography

   Författare :Stephan Hoffmann; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : .... LÄS MER