Hydrodistillation

Nepeta (Lamiaceae) is a genus of perennial or annual herbs found in Asia, Europe and North Africa. About 250 species of Nepeta are reported of which, 67 species are present in Iran. Some species of this genus are important medicinal plants and their extracts have been used for medicinal purposes. Aerial parts of Nepeta sintenisii Bornm. was subjected to hydrodistillation and the chemical composition of isolated essential oil has been analyzed by GC/MS method for first time. Identification of components of the volatile oil was based on retention indices relative to n-alkanes and computer matching with the Wiley275.L library, as well as by comparison of the fragmentation patterns of the mass spectra with those reported in the literature. 

COMPARISON OF ESSENTIAL OIL COMPOSITION OF SALVIA MIRZAYANII OBTAINED BY SUPERCRITICAL FLUID EXTRACTION AND HYDRODISTILLATION METHODS... 

Further more, the essential oils of the plant were isolated by hydrodistillation in Clevenger-type apparatus for 5 hours. The chemical compositions of the SFE extract and hydrodistillation were identified by GC-MS and determined by GC-FID. 

Braga et al. ° compared the efficiencies of several processes, i.e., hydrodistillation, low pressnre solvent extraction, and Soxhlet and supercritical fluid extraction. For each process, the inflnences of several parameters (duration, temperature, nature of solvent) were also evalnated. These authors concluded that the Soxhlet method performed with ethanol/isopropanol 1/100 v/v for 2 hr and 30 min was the most effective. Snn et al. nsed solid phase extraction to concentrate (nine times) a... 

Figure 16.4 displays the separation of the resins of B. carterii and B. serrata, their hydrodistillates, and three commercially available olibanum essential oils on a Merck LiChrospher plate in the mobile phase heptane-diethylether-formic acid (7 + 3 + 0.3 v/v/v) without chamber saturation after derivatization with anisaldehyde reagent. 

Lane 1 displays the separation of the resin of B. carterii and lane 2 and lane 3 its volatile fractions received by hydrodistillation. Accordingly, lane 8 displays the... 

Typical areas of application are identification of trace (ppm or ppb level) volatile organics in complex mixtures (e.g. olfactory principles) and monitoring of residual monomers in polymeric materials. Apart from HS-GC, analysis of volatiles can also be carried out by a variety of other methods, including hydrodistillation, SFE, US, adsorption trapping and SPME. 

M. Khasjeh, Y. Yamini, F. Sefidkon and N. Bahramifar, Comparison of essential oil composition of Carum copticum obtained by supercritical carbon dioxide extraction and hydrodistillation methods. Food Chem. 86 (2004) 587-591. 

In this example different methods of cluster analysis are applied to terpene data from wild growing, flowering Hyptis suaveolens originating from different locations in El Salvador (Grassi et al. 2005) it is a frequently used aromatic and medicinal plant of Central America. The collected plants were hydrodistilled and the resulting... 

Total Oil Determination. The conventional Clevenger hydrodistillation method was used. A 20 g sample was used and the distillation was continued forl6 hours. 

Determination of Total Oil. The Clevenger hydrodistillation method was used for total oil determination (15). Forty gram samples were distilled for 3i hours. However, due to limited availability, some sample sizes were restricted to 20 grams. Volumetric readings were multiplied by the oil density to arrive at the gravimetric values. All samples were analyzed in duplicate. 

The oil value shown for beta-cyclodextrin was an approximation. Clevenger hydrodistillation failed to recover any volatiles from the inclusion complex. An alternate method was attempted using simultaneous steam distillation and solvent extraction. GC quantitation of the recovered volatiles did not yield reproducible results. 

Comparative chemical compositions of the volatile oils of different plants, obtained by hydrodistillation and SFE (% of peak area)... 

Microwave-assisted extractions (MAE) can be performed in open (focused MAE) or closed (pressurized MAE) flasks. This technique is commonly used for extractions from complex and difficult sample matrices, replacing time- and solvent-intensive Soxhlet extractions or hydrodistillations.46 MAE is also widely applied to environmental samples, for example, for extracting polycyclic aromatic hydrocarbons (PAH) from soil, methylmercury from sediments, and trace metals and pesticide residues from plant material47 48 The use of microwave treatment instead of hydrodistillation offers a solvent-free separation technique essential oils are heated and dry-distilled 46... 

Essential oils obtained by hydrodistillation of green and black berries of Indian origin (cv. Thevanmundi) were analysed by GC and GC-MS methods and compared with the reported constituents of Sri Lankan green and... 

A comparison of both the SFME method and hydrodistillation (HD), indicating the difference in the yields of the two major aromatic components, e.g. 1,8-cineole and a-terpinyl acetate, is shown in Table 3.10. Experiment 1 corresponds to the shortest extraction time, 23 min, the lowest irradiation power, 190 W and the lowest moisture content, while Experiment 8 consists of the longest extraction time, the highest irradiation power (340 W) and the highest moisture content (62%). In comparison, HD is... 

The large cardamom pericarp (husk) yielded 0.18% volatile oil by the Clevenger hydrodistillation method. This oil was analysed for physical parameters, e.g. specific gravity (0.9148), refractive index (1.4733) and optical rotation (-7.700). The volatile oil was subjected to GC-MS analysis and 37 compounds were identified, constituting > 98% of the total oil. The major compounds characterized were 1,8-cineole (38.7%), [3-pinene (13.6%), a-terpineol (12.6%), spathulenol (8.3%), 4-terpineol (4.5%), ger-macrene D (3.0%), a-pinene (2.8%) and (3-selinene (2.7%). GC and GC-MS data revealed that 1,8-cineole content was less than 50% when compared with the seed oil. Table 4.5 shows the major constituents separated by GC-MS (Rout et al., 2003). Figure 4.1 gives the structures of the major chemical components in the volatile oil from seeds. 

The pericarp (husk) of large cardamom yielded 0.18% volatile oil by the Clevenger hydrodistillation method. This oil was analysed for physical parameters, e.g. specific gravity (0.9148), refractive index (1.4733) and optical rotation (-7.700). 

The chemical composition of the essential oils obtained from the hydrodistillation of the rhizomes of the common ginger (Z. officinale) grown in Mauritius was analysed by Fakim et al. (2002). The oil was characterized by the presence of geranial (16.3%), neral (10.3%), zingiberene (9.5%), (3-sesquiphellan-drene (6.3%) and ar-curcumene (5.1%). 

The composition and yield of curcuminoids extracted using the existing techniques, e.g. hydrodistillation, low-pressure solvent extraction, soxhlet and SC-C02 extraction, were compared (Braga et al., 2003). The highest yield was obtained using soxhlet extraction with ethanol and the lowest (2.1%) with hydrodistillation. The best solvent for SC-C02 extraction is a mixture of ethanol and isopropanol. ar-Curcumene, z-(y)-atlantone and ( )-(y)-atlantone constituted about 60% of the light fraction. 

Analysis of clove bud oil extracted with liquid and supercritical carbon dioxide showed significant qualitative and quantitative compositional differences compared to oil obtained by the conventional hydrodistillation process. The parameters such... 

Hydrodistillation of coriander seeds yields about 0.35% (w/w) oil based on dry weight (Msaada et al., 2007). Extraction of ripe fruits of C. sativum by steam distillation and by supercritical fluid extraction (SEE), using C02, was compared. The percentage composition of the 40 identified compounds was compared with the composition of commercial coriander oil extracted by hydrodistillation. The oil obtained by SFE showed some quantitative and qualitative differences, giving a superior aroma compared with that of the oil obtained by hydrodistillation (Anitescu et al., 1997). 

Boelens et al. (1990) compared the quality of essential oils from various plant materials for hydrodiffusion and hydrodistillation. Hydrodiffusion oils contained higher levels of oxygenated monoterpenes and benze-noids and possessed preferred olfactive and organoleptic properties. 

Raal et al. (2004) evaluated oil isolated by hydrodistillation from different geographical sources of Europe. Among the 37 components isolated, the major constituent... 

Kosar, M., Ozek, T., Goger, F., Kurkcuoglu, M. and Baser, K.H.C. (2005) Comparison of microwave assisted hydrodistillation and hydrodistillation methods for the analysis of volatile secondary metabolites. Pharmaceutical Biology 43(6), 491-495. 

---