نتایج جستجو برای: supercritical extraction

تعداد نتایج: 174295  

Journal: :Journal of the Fuel Society of Japan 1988

2003
T. Sz. Kristó É. Szőke Á. Kéry P. P. Terdy L. K. Selmeczi B. Simándi

There are many reports on biological activities of pentacyclic triterpenoids, which could be relevant to the pharmacological effects including anti-inflammatory properties. Dandelion (Taraxacum officinale Wiggers et Weber, Asteraceae) is one of the best known European medicinal plants, rich in triterpenoids, which has been used for the treatment of various inflammatory diseases such as rheumato...

2008
A. B. A. de Azevedo Paulo Mazzafera R. S. Mohamed S. A. B. Vieira de Melo T. G. Kieckbusch

The paper reports on experimental data on the extraction of caffeine, coffee oil and chlorogenic acids from green coffee beans using pure supercritical CO2 and supercritical CO2 modified with ethanol (5% w/w) and isopropyl alcohol (5% w/w) at 50 and 60oC and 15.2 24.8 e 35.2 MPa. In this study extraction kinetics were obtained for all assays i.e. samples were collected at several time intervals...

2004
J. D. Hubbard J. M. Downing M. S. Ram O. K. Chung

Cereal Chem. 81(6):693–698 Environmental concerns, the disposal cost of hazardous waste, and the time required for extraction in current methods encouraged us to develop an alternate method for analysis of wheat flour lipids. Supercritical fluid extraction (SFE) with carbon dioxide has provided that medium and the method is fully automatic. Crude fats or nonstarch free lipids (FL) were extracte...

Journal: :Journal of chromatography. A 2012
Victor Abrahamsson Irene Rodriguez-Meizoso Charlotta Turner

A method was developed based on supercritical fluid chromatography for quantitative determination of carotenoids in extracts of Scenedesmus sp. By utilizing the low backpressure in supercritical fluid chromatography, a C18 column and a 2-ethyl pyridine column were coupled in series. It was concluded that even minor changes in temperature had a substantial effect on selectivity. A standard mixtu...

2004
J. A. Lubguban B. Lahlouh T. Rajagopalan N. Biswas S. Gangopadhyay J. Sun D. H. Huang S. L. Simon

We present a supercritical CO 2 (SCCO 2) process for the preparation of nanoporous organosilicate thin films for ultra low dielectric constant materials. The porous structure was generated by SCCO 2 extraction of a sacrificial poly(propylene glycol) (PPG) from a nanohybrid film, where the nanoscopic domains of PPG porogen are entrapped within the crosslinked poly(methylsilsesquioxane) (PMSSQ) m...

2009
Hyang-Min Ahn Md. Salim Uddin

The aromatic compounds of Artemisia annua were extracted by supercritical carbon dioxide. Supercritical carbon dioxide extraction of volatile flavor compounds from Artemisia annua was performed at pressure 150bar and temperature 40oC. The flow rate of CO2 was 20 g/min and the flow rate of ethanol as an entrainer was 5% of CO2 used. The extraction time was 1 h. The trapped sample by cold trap 1 ...

Journal: :Journal of analytical toxicology 1997
K S Scott J S Oliver

A supercritical fluid extraction (SFE) procedure for the analysis of temazepam from whole blood was developed. Quantitative recoveries were obtained by high-performance liquid chromatography using prazepam as an internal standard and carefully monitoring the extraction temperature and pressure. The results were found to compare well with those obtained by solid-phase extraction techniques, but ...

Journal: :Journal of chromatography. A 2000
S B Hawthorne C B Grabanski E Martin D J Miller

Extractions of a polycyclic aromatic hydrocarbon (PAH)-contaminated soil from a former manufactured gas plant site were performed with a Soxhlet apparatus (18 h), by pressurized liquid extraction (PLE) (50 min at 100 degrees C), supercritical fluid extraction (SFE) (1 h at 150 degrees C with pure CO2), and subcritical water (1 h at 250 degrees C, or 30 min at 300 degrees C). Although minor diff...

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