Extraction simultaneous distillation

Maignial, L., Pibrot, P., Bonetti, G., Chaintrau, A., and Marion, J. P. (1992). Simultaneous distillation-extraction under static vacuum Isolation of volatile compounds at room temperature. J. Chromatogr. A 606, 87-94. 

Solid-phase microextraction eliminates many of the drawbacks of other sample preparation techniques, such as headspace, purge and trap, LLE, SPE, or simultaneous distillation/extraction techniques, including excessive preparation time or extravagant use of high-purity organic solvents. SPME ranks amongst other solvent-free sample preparation methods, notably SBSE (Section 3.5.3) and PT (Section 4.2.2) which essentially operate at room temperature, and DHS (Section 4.2.2),... 

QQQ, QqQ Triple quadrupole analyser SDE Simultaneous distillation extraction... 

Besides classical headspace analysis, simultaneous distillation-extraction and solvent extraction, new sampling and enrichment developments include solvent-assisted flavour evaporation (SAFE) [3] and sorptive techniques like SPME solid-phase microextraction (SPME) [4,5] and stir-bar sorptive extraction (SBSE) [6], which are treated in a dedicated chapter in this book. This contribution will deal with advanced developments of GC techniques for improvement of separation and identification (classical multidimensional GC, or... 

Distillation (Simultaneous Distillation/Extraction, Vacuum Distillation)... 

It is very common to combine methods in obtaining aroma isolates. The simultaneous distillation/extraction method previously described is an example. Another popular combination method initially involves the solvent extraction of volatiles from a food and then high-vacuum distillation of the solvent/aroma extract to provide a fat-free aroma isolate. This technique is broadly used today to provide high-quality aroma extracts for numerous purposes. The apparatus used in solvent removal has been improved upon to reduce analysis time and efficiency the modified method is termed solvent-assisted flavour extraction (SAFE) [16]. 

Aroma compounds are present in minute levels in foods, often at the ppb level ( ig/liter). In order to analyze compounds at these levels, isolation and concentration techniques are needed. However, isolation of aroma compounds from a food matrix, which contains proteins, fats, and carbohydrates, is not always simple. For foods without fat, solvent extraction (unit gu) can be used. In foods containing fat, simultaneous distillation extraction (SDE see Basic Protocol 1) provides an excellent option. Concentration of headspace gases onto volatile traps allows sampling of the headspace in order to obtain sufficient material for identification of more volatile compounds. A separate protocol (see Basic Protocol 2) shows how volatile traps can be used and then desorbed thermally directly onto a GC column. For both protocols, the subsequent separation by GC and identification by appropriate detectors is described in unitgu. 

One design of the micro steam simultaneous distillation extraction apparatus is given in Figure G 1.2.1. Both sample and solvent flasks are heated to their boiling points. Vapors coming from the sample and solvent flasks (Figure Gl.2.1, G and F) are mixed in the... 

Figure G1.2.1 Simultaneous distillation extraction system. A, flask for water B, flask for solvent C, separation chamber D, return tube for water E, return tube for solvent F, vapor tube for water G, vapor tube for solvent H, inlet/vent I, cold finger. Modified from Godefroot et al. (1981).

Of the two techniques described here, simultaneous distillation extraction (SDE) is a more complete volatile extraction procedure that serves to obtain quantitative information on the compounds contained in a food. Volatile trapping is a partial extraction procedure that samples the vol a-tiles present in the headspace above a food, which are those with higher volatili ty. Extended trapping also induces additional volatilization of compounds initially contained in the food. 

Chaintreau, A. Simultaneous distillation-extraction From birth to maturity. Review. Flavour Fragrance J. In press. 

Pollien, P. and Chaintreau, A. 1997. Simultaneous distillation-extraction Theoretical model and development of a preparative unit. Anal. Chem. 69 3285-3292. 

SD standard deviation SDE simultaneous distillation extraction SDS sodium dodecyl sulfate SFC solid fat content SFI solid fat index SHAM salicylhydroxamic acid SIM selected ion monitoring SNIF-NMR site-specific natural isotope fractionation measured by nuclear magnetic resonance spectroscopy SP-HPLC straight-phase high-performance liquid chromatography... 

The compound was determined by an isotope dilution assay (J7) in an extract which was obtained by simultaneous distillation/ extraction of the reaction mixture for 2 h. 

Upon employing the more rigorous simultaneous distillation-extraction (SDE) technique (100°C pH 3.7) to isolate the quince fruit volatiles, the resulting aroma composition distinctly differed from that obtained by HVD/SE. After SDE the hydrocarbon 5, the bicyclic alcohol 6 and 3,4-didehydro-(B-ionol (7) were identified as... 

The flavor constituents of plain and roasted cashew nuts have not been previously reported in the literature. In the present study, aroma compounds have been isolated from plain, oven-roasted and oil-roasted cashew nuts by simultaneous distillation extraction and by steam distillation followed by selective extraction, after pH adjustment. Compound identification was carried out by GC and GC-MS analyses. Esters and lactones are present in plain cashews whereas roasted samples also contain pyrazines. 

Simultaneous distillation extraction (SDE) (Total extract) Steam distillation and 100 250 273... 

Isolation of Volatiles by Simultaneous Distillation/ Extraction. The dark brown reaction mixture was placed in a 4 1 round bottom flask and continuously extracted for seven hours with 200 ml pentane/diethy1 ether (1 1) at atmospheric pressure according to the procedure described by Likens/Nickerson. The pentane/ether extract... 

Caja, M.M., Ruiz del Castillo, M.L., Herraiz, M. and Blanch, G.P. (1999) Study of the enantiomeric composition of chiral constituents in edible oils by simultaneous distillation-extraction. Detection of adulterated olive oils. J. Am. Oil Chem. Soc., 76, 1027-1030. 

In the laboratory, a multi-stage liquid-liquid extraction can be performed by a simultaneous distillation-extraction process according to Likens-Nickerson [29] (Fig. 2.10). Here, the liquid matrix with the solute in one flask is evaporated together with an immiscible solvent in a second flask. Extraction takes place in the vapour phase where an intensive distribution of both phases is ensured. The condensed vapours from the two phases are separated via a siphon using their different densities and their reintroduction into the original flasks. As the distillation process is continued, extraction is repeated until the solute is exhausted in the original matrix. This method is very useful when traces of non-volatile solutes are present, which are only partly miscible... 

The sample is diluted with the 10-fold quantity of distilled water and extracted for several hours with dichloromethane or diethylether using a Simultaneous Distillation-Extraction Apparatus (SDE). The organic phase is dried and concentrated by solvent evaporation using a Vigreux column. The concentrated extract can be applied to GC-analysis. This method is applicable for solid, viscous or pasty extracts and flavouring compounds [4],... 

Volatile Compounds in Thalli Culture. A large mass of clean thalli culture, regenerated from protoplasts of U. pertusa, was obtained by cultivation in Provasoli s enriched sea water containing antibiotics (56). The essential oil was prepared from the thalli culture by a simultaneous distillation extraction (SDE) procedure (57). The yield of the essential oil was 8.0 X 10-3% (cf. 4.2 X 10-3% for the field fronds). Twenty-three of the volatile compounds in the oil were identified by GC and GC-MS (Table IV). The major characteristic compounds were long-chain fatty aldehydes as in the oil from the field fronds mainly -pentadecanal, (Z, Z, Z)-7,10,12-hexadecatrienal, (Z)-8-heptadecenal, (Z, Z)-8, 11-heptadecadienal, and (Z, Z, Z)-8, 11, 14-heptadecatrienal. They accounted for ca 40% of the oil and were considered to have the... 

Isolation and separation of volatile oils. The peels (605 g) were chopped into small pieces. The chopped pieces were mixed with de-ionized water (2.2 L) and homogenized at 0 C for 15 minutes. Volatiles were extracted from the homogenized mixture (300 g aliquot) with two portions (30 mL) of ethyl ether by simultaneous distillation extraction (SDE) for 60 minutes. The extracts were combined, and the solvent was removed by evaporation under reduced pressure and under nitrogen atmosphere for 5 hours. The amount of volatile oils was 5.7 g (0.94% yield). The essential oil (4.0 g) was fractioned by silica gel column chromatography (30 cm X 3 cm id) with pentane (1000 mL) and diethyl ether (1000 mL) as eluants. The solvents were partially removed by evaporation. Each fraction was concentrated at room temperature under purified nitrogen. The yields were pentane fraction, 98.18%, and ether fraction, 1.82%. 

The contents of volatile acids of green and roasted coffee were studied by Wohrmann et al. (1997a). By means of simultaneous distillation/extraction (SDE), ion exchange and GC/FID, they identified and quantified 12 acids, including volatile saturated and unsaturated aliphatic acids which have a rancid and sweaty character. 

Identified by Heins et al. (1966) in a headspace analysis of commercial roasted beans and by Merritt et al. (1970) in green and roasted (400-430 °F, ca 205 240 °C) beans. Silwar et al. (1987) gave a concentration of 0.10-0.15 ppm in roasted coffee. It is present in the analysis of Puerto Rico Rio and healthy green beans (simultaneous distillation-extraction, GC/MS) by Spadone et al. (1990) and in the green Mexican coffee analyzed by Cantergiani et al. (2001). 

Identified in raw coffee by Gutmann et al. (1979). It was also found by Cros et al. (1980) by trapping the headspace components of roasted coffee on Tenax GC (polymer of 2,6-diphenyl-p-phenylene oxide) followed by heat desorption. Studying Rio off-flavor, Spadone and Liardon (1988) found /n-xylene in green beans, healthy or not (after simultaneous distillation-extraction). Procida et al. (1997) identified it in headspace of green coffee (six arabicas and six robustas) but not of roasted coffee (one arabica). After extraction of a brewed arabica (see A.50), it was identified by Ramos et al. (1998). 

It was found also by Silwar (1982). Silwar et u/.(1987) give a concentration of 0,20-0,30ppm (steam distillation then simultaneous distillation-extraction). Holscher and Steinhart (1995) identified this alcohol in green coffee with a concentration of 0.53 ppm. 

Identified by Stoll et al. (1967) and found in green Rio coffee and a Santos reference (in a lower concentration) by Spadone and Liardon (1988). The same group (Spadone et al., 1990) could identify this compound (simultaneous distillation-extraction) in green beans of a Puerto Rico Rio coffee but not in a healthy variety. By headspace analysis of a roasted Columbian coffee, Ho et al. (1993) found a concentration of 0.12 ppm. 

Identified by Wang et al. (1983) (headspace) and in green Columbian coffee by Holscher and Steinhart (1995) who gave a concentration of 0.104 ppm (simultaneous distillation extraction). It was found in the extract of a brew with supercritical CO2 by Ramos et al. (1998) (see C.3). 

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