نتایج جستجو برای: supercritical extraction

تعداد نتایج: 174295  

2003

Solid phase extraction (SPE) and supercritical fluid extraction (SFE) have become established in the field of analytical chemistry over the last five years. Both techniques are alternatives to classical analytical extraction methods used to separate analytes from solid and liquid matrices. SFE is an alternative to traditional liquid-solid extraction methods, the two most common being soxhlet an...

2004
Beatriz P. Nobre António F. Palavra Rui L. Mendes

Supercritical CO2 extraction of carotenoids from tomato industrial wastes (mixture of skins and seeds) was carried out in a flow apparatus at the temperature of 60 oC and the pressure of 300 bar. The effect of the moisture content (4.6, 23 and 58%), particle size (0.15, 0.35 and 0.72 mm) and solvent flow-rate was studied. The carotenoids recovery (mass of extracted compounds by supercritical CO...

Journal: :Talanta 2001
Q Lang C M Wai

Due to increasingly stringent environmental regulations, supercritical fluid extraction (SFE) has gained wide acceptance in recent years as an alternative to conventional solvent extraction for separation of organic compounds in many analytical and industrial processes. In the past decade, SFE has been applied successfully to the extraction of a variety of organic compounds from herbs and other...

2006
David A. Ward

INTRODUCTION A sol-gel preparation involves f m t the formation of a sol, which is a suspension of solid particles in a liquid, then of a gel, which is a diphasic material with a solid encapsulating a liquid. The liquid can be removed from a gel by either conventional drying (such as by using an oven) to obtain a plojiict kLown as e xercgel, or hy drying with supercritical extraction (often ref...

2007
Scott L. Taylor

The total oil content of soyflakes, canola seed and wetmilled corn germ were determined by analytical supercritical fluid extraction (SFE) with carbon dioxide as the extraction solvent. Results obtained by SFE were in excellent agreement with those obtained by a conventional Soxhlet technique with organic solvents. The analyticalscale SFE technique yielded average means within one standard devi...

Journal: :Analytical sciences : the international journal of the Japan Society for Analytical Chemistry 2004
Tetsuo Sakamoto Azusa Yamamoto Masanori Owari Yoshimasa Nihei

A novel sample-pretreatment method for time-of-flight secondary ion mass spectrometry (TOF-SIMS) was developed using supercritical fluid extraction (SFE). In SFE, the extraction efficiency of a certain organic matter is controlled by the pressure and temperature of supercritical CO2. Two-step SFE (1st step at 10 Mpa, 40 degrees C; 2nd step at 30 MPa, 120 degrees C) was applied to diesel exhaust...

2004
Wei Wei Jianzhong Yin Che Zhu Yi Liu Wenhua Shi

As the development of the natural medicine, the glycyrrhizin extracted from the licorice root was found to have potential therapeutic value in the treatment of several diseases, especially available for anti-SARS virus . Therefore, the purpose of this work was to find an optimal method to extract and refine the glycyrrhizin. In this work, the extraction of glycyrrhizin by means of organic solve...

2010
E. V. Lau S. Gan H. K. Ng

This paper aims to provide a review of the analytical extraction techniques for polycyclic aromatic hydrocarbons (PAHs) in soils. The extraction technologies described here include Soxhlet extraction, ultrasonic and mechanical agitation, accelerated solvent extraction, supercritical and subcritical fluid extraction, microwave-assisted extraction, solid phase extraction and microextraction, ther...

2003
MARTHA J. M. WELLS Somenath Mitra

This chapter focuses on three widely used techniques for extraction of semivolatile organics from liquids: liquid–liquid extraction (LLE), solid-phase extraction (SPE), and solid-phase microextraction (SPME). Other techniques may be useful in selected circumstances, but these three techniques have become the extraction methods of choice for research and commercial analytical laboratories. A fou...

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