Pressurized-fluid extraction

ScHANTZ MM, Nichols JJ, and Wise SA (1997b) Evaluation of pressurized fluid extraction for the extraction of environmental matrix reference materials. Anal Chem 69 4210-4219. 

Pressurized Fluid Extraction followed by Gas Chromatography/Mass Spectrometry (PFE-GC/MS) On-line Supercritical Fluid Extraction - Gas Chromatography/Mass Spectrometry (SFE-GC/MS)... 

More elaborate sample preparation is often needed for complex sample matrices, e.g., lotions and creams. Many newer SP technologies such as solid-phase extraction (SPE), supercritical fluid extraction (SFE), pressurized fluid extraction, accelerated solvent extraction (ASE), and robotics are frequently utilized (see Ref. [2]). Dosage forms such as suppositories, lotions, or creams containing a preponderance of hydrophobic matrices might require more elaborate SP and sample cleanup, such as SPE or liquid-liquid extraction. 

M.D. David, S. Campbell and Q.X.Li, Pressurized fluid extraction of nonpolar pesticides and polar herbicides using in situ derivatization. Anal. Chem. 72 (2000) 3665-3670. 

Camel, V. 2001. Recent extraction techniques for solid matrices-supercritical fluid extraction, pressurized fluid extraction and microwave-assisted extraction Their potential and pitfalls. Analyst 726 1182-1193. 

ASE—also referred to as pressurized fluid extraction (PFE)—offers an order of magnitude of additional reductions in solvent use with faster sample processing time, and with the potential of automated, unattended extraction of multiple samples. Briefly, with ASE a solid sample is enclosed in a cell containing an extraction solvent after the cell has been sealed, the sample is permeated by... 

Ryno, M., L. Rantanen, E. Papaioannou, A.G. Konstandopoulos, T. Koskentalo, and K. Savela. 2006. Comparison of pressurized fluid extraction, Soxhlet extraction and sonication for the determination of polycyclic aromatic hydrocarbons in urban air and diesel exhaust particulate matter. J. Environ. Monit. 8 488 193. 

Accelerated solvent extraction (ASE) is also known as pressurized fluid extraction (PFE) or pressurized liquid extraction (PLE). It uses conventional solvents at elevated temperatures (100 to 180°C) and pressures (1500 to 2000 psi) to enhance the extraction of organic analytes from solids. ASE was introduced by Dionex Corp. (Sunnyvale, CA) in 1995. It evolved as a consequence of many years of research on SFE [45], SFE is matrix dependent and often requires the addition of organic modifiers. ASE was developed to overcome these limitations. It was expected that conventional solvents would be less efficient than supercritical fluids, which have higher diffusion coefficients and lower viscosity. However, the results turned out to be quite the opposite. In many cases, extraction was faster and more complete with organic solvents at elevated temperature and pressure than with SFE. Extensive research has been done on the extraction of a variety of samples with ASE. ASE was approved by EPA as a standard method in 1996. 

Yandenburg et al. [92] compared extraction of additive Irganox 1010 from freeze-ground polypropylene polymer by pressurized fluid extraction (PFE) and MAE with reflux, ultrasonic, shake-flask, and Soxhlet extraction. PFE and MAE were faster than any conventional method with comparable extraction efficiency. The times to reach 90% recovery by PFE using propan-2-ol at 150°C and acetone at 140°C were 5 and 6 minutes, respectively. Reflux with chloroform was found to be the fastest method performed under atmospheric pressure with 90% recovery in 24 minutes. Reflux with cyclohexane propan-2-ol (1 1) required 38 minutes. Ultrasonic, shake-flask, and Soxhlet extraction required about 80 minutes (90%) extraction). The total sample preparation time for PFE was 15 minutes, MAE 28 minutes, and reflux with chloroform was 45 minutes. 

Pressurized solvent extraction (PSE), also called pressurized fluid extraction (PEE), accelerated solvent extraction (ASE ), pressurized liquid extraction (PEE), or enhanced solvent extraction (ESE), is a solid-liquid extraction that has been developed as an alternative to conventional extractions such as Soxhlet, maceration, percolation, or reflux. It uses organic solvents at high pressure and temperature to increase the efficiency of the extraction process. Increased temperature decreases the viscosity of the liquid solvent, enhances its diffusivity, and accelerates the extraction kinetics. High pressure keeps the solvent in its liquid state and thus facilitates its penetration into the matrix, resulting in increase extraction speed [30]. 

A variety of solvent extraction techniques have been used to extract antioxidants from food matrices. The most commonly used is maceration or homogenization of the sample with an extraction solvent however, alternative procedures have been developed including pressurized fluid extraction (PFE), ultrasound-assisted extraction (UAE), microwave-assisted extraction (MAE), and matrix solid-phase dispersion (MSPD), among others. The principles of each extraction technique will be briefly discussed. 

Pressurized fluid extraction is another technology that applies high pressure extraction solution in the sample matrix to perform extraction. The solution is water or water mixed with different polar solvents, and its extraction pressure is lower than 1 atm. The extraction solvent and sample can be heated to 200 °C to weaken the sample matrix and allow solvent to penetrate. Compared to traditional extraction methods, pressurized fluid extraction has short extraction time and requires less solvent. As with other extraction methods, extraction temperature and pressure and solvent composition are very critical to the phenolic acid extraction yield (Palma et al., 2001, 2002 Mukhopadhyay et ah, 2006). 

Pahna, M. Pineiro, Z. Barroso, C.G. 2002. In-line pressurized-fluid extraction-solid-phase extraction for determining phenolie eompounds in grapes. J. Chromatogr. A. 968 1-6. 

Dongjin, P. Soyoung, L. Rapid purification of micro-cystin-LR using supercritical fluid exteraction and flash chromatography. Anal. Lett. 2002, 35 (9), 1591-1602. Camel, V. Recent extraction techniques for solid matrices—Supercritical fluid extraction, pressurized fluid extraction and microwave-assisted extraction Their potential and pitfalls. Analyst 2001, 126, 1182-1193. 

Alternatively, one could use a Soxhlet or similar apparatus to extract the sample. Other methods to prepare a sample for analysis through extraction include supercritical fluid extraction (SFE), pressurized fluid extraction, and microwave-assisted solvent extraction. 

The accelerated solvent extraction (ASE) system introduced by Dionex uses standard solvents at elevated temperatures and pressures to increase extraction efficiency. Samples are placed in stainless-steel extraction vessels that are loaded into the ASE that has been programmed for the extraction protocol. The instrument allows for the unattended extraction of 24 samples. The initial units allowed for solvent blending by premixing solvents before they were placed into the ASE. Recent modifications allow solvent blending to be accomplished in-line. There has been some controversy about the use of the name ASE because it points to instrumentation from one company and other companies have introduced competing products. It has been proposed that the ASE technology be more correctly referred to as pressurized fluid extraction because ASE denotes a commercial device. 

To understand the theory relating to pressurized fluid extraction (PFE). 

Pressurized fluid extraction uses heat and pressure to extract analytes rapidly and efficiently from solid matrices. For background information on pressurized fluid extraction, see Box 7.2. 

Since pressurized fluid extraction (PFE), also known as accelerated solvent extraction (ASE ), is a relatively new technique, the commercial availability of PFE instruments is limited. A commercial PFE system ( ASE 200 ) currently available is a fully automated sequential extractor developed by the Dionex Corporation, USA. This mainly consists of a solvent-supply system, extraction cell, oven, collection system and purge system, all of which are under computer control. A schematic diagram of a PFE system is shown in Figure 7.15. This system (ASE 200) can operate with up to 24 sample-containing extraction vessels and up to 26 collection vials, plus an additional four vial positions for rinse/waste collection. 

Figure 7.15 Schematic of the layout of a typical pressurized fluid extraction system. DQ 7.12...

Figure 7.16 Typical procedure used for the pressurized fluid extraction (or accelerated fluid extraction) of solids.

Example 7.6 Pressurized Fluid Extraction of DDT, DDD and DDE from Contaminated Soif... 

Figure 7.17 Results obtained for the pressurized fluid extraction of DDT, DDD and DDE from contaminated soil, and comparison with those obtained from Soxhlet extraction , Soxhlet PFE 1, DDT 2, DDD 3, DDE [6] (cf. DQ 7.13).

Accelerated solvent extraction (pressurized fluid extraction) Semi-volatiles and non-volatile organics from soils, relatively dry sludges and solid wastes Extraction under pressure using small volumes of organic solvent... 

First of all, it is important to identify what the acronyms represent. The following have been used aMAE, atmospheric microwave-assisted extraction SFE, supercritical fluid extraction pMAE, pressurized microwave-assisted extraction PFE, pressurized fluid extraction ASE, accelerated solvent extraction MSPD, matrix solid-phase dispersion. 

Accelerated solvent extraction (ASE) Method of extracting analytes from matrices using a solvent at elevated pressures and temperatures (see also Pressurized fluid extraction). 

The focus in Chapters 7 and 8 is on the specific sample preparation approaches available for the extraction of organic compounds from environmental matrices, principally soil and water. Chapter 7 is concerned with the role of Soxhlet, ultrasonic and shake-flask extraction on the removal of organic compounds from solid (soil) matrices. These techniques are contrasted with newer developments in sample preparation for organic compound extraction, namely supercritical fluid extraction, microwave-assisted extraction and pressurized fluid extraction. Chapter 8 is arranged in a similar manner. Initially, details are provided on the use of solvent extraction for organic compounds removal from aqueous samples. This is followed by descriptions of the newer approaches, namely solid-phase extraction and solid-phase microextraction. 

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