Simultaneous steam distillation/extraction

During, R.A., X. Zhang, H.E. Hummel, J. Czynski, and S. Gath. 2003. Microwave-assisted steam distillation with simultaneous liquid/liquid extraction of pentachlorophenol from organic wastes and soils. Anal. Bioanal. Chem. 375 584—588. 

Hydrolysed protein preparations have been used to attract various insects. The general subject of insect attractant use both in nature and by man is introduced, with particular reference to the Tephritid family of fruit flies. The work of the Biocommuni-cation Chemistry Research Unit on the identification of the active attractant compounds in the hydrolysed corn protein, Nu-Lure Insect Bait (NLIB) is discussed. Different isolates have been obtained by running simultaneous steam distillation-extractions (SDE) under vacuum and atomospherlc pressure and under basic and acidic conditions. Chemical fractionation of these isolates has also been accomplished. Chemical identification by gas chromatography/mass spectrometry (gc/ms) is discussed. 

We are examining those commonly used baits, the protein hydrolysates. Initial studies have used the corn gluten hydrolysate commonly known as PIB-7 or, now, as Nu-Lure Insect Bait (NLIB). This material was used in the recent successful Medfly eradication program in California. Since the fruit flies are probably attracted to the volatile emanations from the bait, we have used equipment and techniques previously developed by members of our group for flavor research. For example, a modified Likens-Nickerson simultaneous steam distillation-extraction head was developed by Flath and Forrey (67.). Also, there is a 90 liter... 

Our first separation method involved running the simultaneous steam distillation extraction under 100 mm vacuum in order to minimize heat effects. This was followed by extraction under atmospheric pressure in order to get more complete recovery. This atmospheric extraction was run for 10 days, using a fresh hatch of solvent each day (68-69). Approximately 10 times as much material was collected each day at atmospheric pressure as was collected under vacuum. Since Schultz, et. al. (70) showed that many non-water-soluble alcohols, esters, aldehydes, and ketones can he recovered by this system in less than 3 hours, the collection of a large amount of material after 10 days is indicative of a very complex and probably dynamic system. Gas chromatograms for these extracts (68.) and some compound identifications (69.) have been reported. (Other reports on the identification of volatiles from protein hydrolysates are given In references 71-75). Prelminary results have shown that the vacuum extracts are more attractive for the Medfly than the atmospheric ones. 

High resolution fused silica capillary columns were used to examine, and in some cases to compare, flavor and aroma essences obtained by 1) direct headspace injection, 2) simultaneous steam distillation extraction, 3) standard Soxhlet extraction using dichloromethane, and 4) high pressure Soxhlet extraction using liquid CO2 Developments in smaller- and larger-diameter fused silica open tubular columns, and columns coated with a bonded polyethylene glycol stationary phase were also explored. 

Simultaneous Steam Distillation/Extraction An elegant apparatus was described by Nickerson and Likens ( 5) for the simultaneous steam distillation and extraction (SDE) of volatile components. This device has become one of the mainstays in the flavor field. In this apparatus, both the aqueous sample and water-immiscible solvent are simultaneously distilled. The steam which contains the aroma chemicals and the organic solvent are condensed together, and the aroma compounds are transferred from the aqueous phase to the organic phase. Typical solvents used are diethyl ether, pentane or a mixture thereof normal extraction times are one to two hours. 

Figure 10. simultaneous steam-distillation extraction SDE) head. (Reproduced from Ref. 26. Copyright 1977, American Chemical Society). 

Figure 2. Simultaneous steam distillation-extraction (Likens-Nickerson)...

IRMS LC MDGC MS MSA NIF NMR OAV OSV PCA RAS RP SDE SFE SIM SNIF SPME TIC TLC Stable Isotope Ratio Mass Spectrometry Liquid Chromatography MultiDimensional Gas Chromatography Mass Spectrometry Multivariate Sensory Analysis Nasal Impact Frequency Nuclear Magnetic Resonance spectroscopy Odor Activity value Odor Spectrum Value Principal Component Analysis Retronasal Stimulation Reversed Phase Simultaneous steam Distillation Extraction Supercritical Fluid Extraction Selected Ion Monitoring Surface of Nasal Impact Frequency Solid Phase Micro Extraction Total Ion Current Thin Layer Chromatography... 

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 Vitzthum and Werkhoff (1974a,b). Silwar et al. (1986) after steam distillation/extraction, used flame ionization and flame photometric detectors simultaneously for the sulfur compounds. They found contents of 0.4-0.45 ppm in arabicas and 0.65-0.70 in robustas. Tressl (1989) reported 0.5-1 and 0.8-1.5 ppm. 

Many of the medicinal properties, including antidermatophytic, of P. frutescens have been reported [164-167]. A steam distillate was obtained from partially dried P. frutescens leaves commercially cultivated in California using simultaneous steam distillation-extraction. Finely macerated leaves (39.2 grams) were combined with approximately 600 mL of distilled water in a round bottom flask. The flask was then connected to a Likens-Nickerson distillation-extraction head. Pentane was used as the extraction solvent and the distillation was allowed to proceed for approximately 90 minutes. This process yielded 0.3 grams (0.77%) of an aroma concentrate possessing a characteristic "shiso" aroma. The antimicrobial activity of shiso, in relation to its traditional use in sashimi dishes, has been studied [168],... 

MSDE = Micro-simultaneous steam distillation extraction... 

A more general purpose steam distillation/extraction apparatus is the steam codistillation extractor (SCDE) allows simultaneous condensation... 

From Takeoka et al. (1996). Soybean and cottonseed oils used to fry meat products. Analysed by capillary gas chromatography of fractions isolated by simultaneous steam distillation-extraction. 

Several techniques for the removal of volatile compounds associated with flavor from foods have been reported dynamic headspace (DHS) and purge and trap (PT) [7 9], solvent extraction [10], high vacuum distillation and steam distillation [11], simultaneous steam distillation extraction (SDE) [8,11,12], supercritical fluid extraction (SFE) [13-15], and solid-phase microextraction (SPME) [16,17],... 

One of the most popular and valuable techniques in the flavor analysis fleld is the simultaneous steam distillation/extraction (SDE) apparatus first described by Likens and Nickerson (17). The apparatus provides for the simultaneous condensation of the steam distillate and an immiscible organic solvent. Both liquids are continuously recycled, and thus the steam distillable-solvent soluble compounds are transferred from the aqueous phase to the solvent. The advantages of this system include the following ... 

The alkylborane is then oxidized by the addition of 150 ml of a 15% solution of hydrogen peroxide, while the pH of the reaction mixture is maintained at 7-8 by the simultaneous addition of 3 Asodium hydroxide, the process being carried out at ice-bath temperature. The reaction mixture is neutralized and subjected to steam distillation. The distillate is extracted with ether, and the extract is dried over anhydrous magnesium sulfate. After removal of the ether, distillation yields 18.0 g (70%) of n-octanal, bp 83-85733 mm. 

In liquid-solid extraction (LSE) the analyte is extracted from the solid by a liquid, which is separated by filtration. Numerous extraction processes, representing various types and levels of energy, have been described steam distillation, simultaneous steam distillation-solvent extraction (SDE), passive hot solvent extraction, forced-flow leaching, (automated) Soxh-let extraction, shake-flask method, mechanically agitated reflux extraction, ultrasound-assisted extraction, y -ray-assisted extraction, microwave-assisted extraction (MAE), microwave-enhanced extraction (Soxwave ), microwave-assisted process (MAP ), gas-phase MAE, enhanced fluidity extraction, hot (subcritical) water extraction, supercritical fluid extraction (SFE), supercritical assisted liquid extraction, pressurised hot water extraction, enhanced solvent extraction (ESE ), solu-tion/precipitation, etc. The most successful systems are described in Sections 3.3.3-3.4.6. Other, less frequently... 

Applications Simultaneous steam distillation-solvent extraction has been in use for many years [163]. Steam distillation combined with continuous liquid extraction is an efficient technique for the removal and isolation of volatile compounds in various matrices (environmental,... 

Seidel V, Lindner W. 1993. Universal sample enrichment technique for organochlorine pesticides in environmental and biological samples using a redesigned simultaneous steam distillation-solvent extraction apparatus. Anal Cem 65 3677-3683. 

Essences of pink and white fresh guava obtained by direct extraction of flesh juices with dichloromethane revealed that the total amount of Cs aldehydes, alcohols, and acids comprised 20 and 44% of the essence of fresh white and pink guavas, respectively [49]. The flavour of the Costa Rican guava has been described as sweet with strong fruity, woody-spicy, and floral notes [53]. One hundred and seventy-three volatile compounds were isolated by simultaneous steam distillation-solvent extraction. The terpenes and terpenic derivatives were found in this fruit in major concentrations and were strong contributors to tropical fruit notes (Fig. 8.1). The aliphatic esters contributed much to its typical flavour. 

Volatile compounds isolated from strawberry guava fruit by simultaneous steam distillation-solvent extraction were identified by capillary gas chromatography-mass spectrometry (GC-MS) and were characterised sensorially by sniffing GC [52]. Terpenes and terpenic derivatives were identified and were shown to contribute much to the typical strawberry guava flavour. The presence of many aliphatic esters and terpenic compounds is thought to contribute to the unique flavour of the strawberry guava fruit. 

Another investigation reported the esters as the predominant volatile components of the Maradol variety (about 41% w/w of the total volatiles) [51]. The major representative compounds in the simultaneous steam distillation-solvent extraction were methyl butanoate and ethyl butanoate. Previous work described the esters as the predominant compounds among the volatiles papayas, for example, from Sri Lanka and Colombia had 52 and 63% of esters in the total volatiles respectively [25,41]. 

More recently, several aroma compounds were isolated from cupuacu pulp by vacuum distillation, solid-phase extraction, and simultaneous steam distil-lation-extarction and were analysed by GC, GC-MS, and GG-O [8]. The olfaction of the extracts obtained by solid-phase extraction indicated linalool, a-ter-pineol, 2-phenylethanol, myrcene, and limonene as contributors of the pleasant floral flavour. In this study, the esters ethyl 2-methylbutanoate, ethyl hexanoate, and butyl butanoate were involved in the typical fruity characteristics. 

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