Clevenger

Many procedures have been developed, but two in particular have been more widely used the Coe and Clevenger approach and the Kynch method as defined by Talmage and Fitch (op. cit.). 

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. 

Coe and Clevenger method. Since the slurry settling rate R varies with concentration of solids in the thickener batch settling tests are used to determine R over the concentration range of operation F S) and the corresponding... 

Coe, H.S. and Clevenger, G.H., 1916. Methods for deteiTnining the capacities of slime thickening tanks. Transactions of the American Institute of Mining Engineers, 55, 356-384. 

D. Duebelbeis, S. Kapila, T. E. Clevenger and A. P. Yanders, Application of a two-dimensional reaction cliromatography system for confiimatoiy analysis of Chlordane constituents in environmental samples. Chemosphere 20 1401 -1408 (1990). 

Clevenger, A.P., Purroy, F.J. and Pelton, M.R. 1992 Food habit ofbrown bears fUrsus arctos) in the Cantabrian mountains, Spain. Journal ofMammalogy 73 415 21. 

Emulsions and aqueous discharges were analyzed for pH, soluble solids (°Brix), recoverable oil with the Clevenger method [19], total pectin substances as anhydrogalacturonic acid [20,... 

The protocol involving NaOAc-HOAc at pH 5 was first proposed and used by Jackson (1958) to remove carbonates from calcareous soils to analyze soil cation exchange characteristics (Grossman and Millet, 1961). Other researchers used HOAc for the extraction of metals from sediments and soils (Nissenbaum, 1972 Mclaren and Crawford, 1973). Tessier et al. (1979) first used the NaOAc-HOAc solution at pH 5 to dissolve the carbonate fraction from sediments. Since then, the NaOAc-HOAc buffer has been widely used as a specific extractant for the carbonate phase in various media (Tessier et al., 1979 Hickey and Kittrick, 1984 Rapin et al., 1986 Mahan et al., 1987 Han et al., 1992 Clevenger, 1990 Banin et al., 1990). Despite its widespread use, this step is not free from difficulties, and further optimization is required in its application. Questions arise with regard to this step in the elemental extraction from noncalcareous soils, the dissolution capacity and dissolution rates imposed by the buffer at various pHs, and the possibility that different carbonate minerals may require different extraction protocols (Grossman and Millet, 1961 Tessier et al., 1979). 

Clevenger T.E. Use of sequential extraction to evaluate the heavy metals in mining wastes. Water Air Soil Pollut 1990 50 241-254. 

Fahim MS, Fahim Z, Harman JM, Clevenger TE, Mullins W, Hafez ES. (1982). Effect of Panax ginseng on testosterone level and prostate in male rats. Arch Androl. 8(4) 261-63. 

Puri, R.K., Clevenger, T.E., Kapila, S., Yanders, A.F., and Malhotra, R.K. Studies of parameters affecting translocation of tetrachlorodibenzo-p-dioxin in soil, Chemosphere, 18(1-6) 1291-1296, 1989. 

Lovenberg TW, Liaw CW, Grigoriadis DE, Clevenger W, Chalmers DT, DeSouza EB, Olters-dorf T (1995) Cloning and characterization of a fimctionally distinct corticotropinreleasing factor receptor subtype from rat braiu. Proc Natl Acad Sci USA 92 836-840... 

Analysis of Spray Dried Samples. Moisture content was determined in duplicate via toluene distillation and total volatile oil by Clevenger (l ). Surface oil was measured by Soxhlet extraction (2). Shelf-life was determined by gas chromatography (6) the end of shelf-life was the time taken (at 37 C storage) to reach a limonene epoxide concentration of 2 mg/g oil. 

Total Oil. Total oil was determined using a Clevenger apparatus. Twenty g powder was dissolved in 150 mL water in a 500 mL flask. 

A few boiling chips and ca. 0.5 mL antifoam emulsion were added. The Clevenger apparatus was fitted into the top of the flask with a water cooled condenser on top of the Clevenger. The solution was slowly brought to a boil and allowed to distill for 3 hr. 

Sensory Analysis. A paired comparison test was run to determine if the difference in oil droplet size in the emulsion changed the perceived intensity of the orange flavor. The coarsest emulsion (3.87 pM) and the Microfluidized sample (0.90 pM) from the third set of spray dried samples were compared. The solutions were prepared using 200 ppm flavor in a 10% (w/v) sucrose solution with 0.30% of a 50% citric acid solution added. The amount of each powder required to attain 200 ppm orange oil was calculated on the basis of percent oil in each powder (determined by Clevenger analysis). A pair of samples at approximately 10 C was given to each of 24 untrained panelists. The samples were coded with random numbers. Half the panelists were asked to taste the coarsest sample first while while the other half tasted the Microfluidized sample first. This was done to determine whether or not adaptation was a factor. The panelists were asked to indicate which sample had the most intense orange flavor. 

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. 

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