H extractants

It was later proposed that more suitable extractants to overcome, and also measure, the salt effects which displace hydrogen ions in a seasonal manner would be either 0.1 M KCI or 0.01 M CaCl2, with the latter being more widely used (Schofield and Taylor, 1955). 

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FIG. 13-7 Separation operations related to distillation, (a) Flush vaporization or partial condensation, (h) Absorption, (c) Rectifier, (d) Stripping, (e) Reboded stripping, (f ) Reboiled absorption, (g) Refluxed stripping, (h) Extractive distillation. ( ) Azeotropic distillation. 

A solution of 1 equivalent of the oxazolidinone in diethyl ether is cooled to —78 C. To the resultant suspension are added 1.4 equivalents of triethylamine. followed by 1.1 equivalents of dibutylboryl triflate. The cooling bath is removed and the reaction mixture is stirred at 25 °C for 1.5 h. The resultant two-phase mixture is cooled to — 78 "C with vigorous stirring. After 1 equivalent of aldehyde is added, the reaction is stirred at —78 °C Tor 0.5 h, and 0 "C for 1 to 2 h. The solution is diluted with diethyl ether, washed with 1 N aq sodium bisulfate, and concentrated. Following oxidation with 30% aq hydrogen peroxide (10 equivalents, 1 1 methanol/water, 0 C. 1 h), extractive workup and chromatographic purification, the aldol adduct is obtained with >99% diastcrcomeric purity. 

Starmans, D.A.J. and Nijhuis, H.H., Extraction of secondary metabolites from plant material a review. Trends Food Sci. Technol., 7, 191, 1996. 

Reflux extraction of additives and wax from polyolefins was reported [116]. Subsequently, the additives were adsorbed onto an adsorbent (Florisil) and the wax was removed from the extract before chromatography. Boiling extractions of SBR are described in ASTM D 1416-89 1 g of rubber is extracted by boiling in two 100 mL portions of 75/25 vol% isopropyl alcohol/toluene. Reflux heating with strong solvents, such as THF, dichloromethane or chloroform has been reported [117]. Reflux extraction has also been used for the 3 h extraction of caprolactam and oligomers from PA6 in boiling methanol. 

Bromo-l-phthalimidopentane 3 was obtained in 72-82 g yield by refluxing 92 g of 1,4-dibromopentane 1, 55.5 g of potassium phthalimide 2, and 200 mL dry acetone on a steam bath for 30 h. Compound 3 (30 g) and 42 g 6-methoxy-8-aminoquinoline 4 refluxed at 130-135 °C for 6 h, extracted with benzene to separate insoluble 6-methoxy-8-aminoquinoline hydrobromide, the residue from evaporation of the benzene was refluxed with stirring with 100 mL of an alcoholic solution of 6 g hydrazine hydrate for 4 h, the solution was concentrated, made acidic to Congo red with 8 N hydrochloric acid, filtered, and washed with boiling water. The combined filtrate and washings was concentrated, made alkaline, extracted with benzene, and distilled in vacuo to give 20.5 g primaquine 6, which was treated with 19 mL 85% phosphoric acid in absolute ethanol, formed 42.5% primaquine diphosphate. 

Suyama, T. Awakura, Y. Hirato, T. Konto, M. Majima, H. Extraction and stripping characteristics of Ni(II) with di(2-ethylhexyl)phosphoric acid under a high electrostatic field. Mater. Trans. JIM 1993, 34, 37 12. 

Zhang, P. W. Inoue, K. Yoshizuka, K. Tsuyama, H. Extraction and selective stripping of molybdenum(VI) and vanadium(IV) from sulfuric acid solution containing aluminum(III), cobalt(II), nickel(II) and iron(III) by LIX 63 in Exxsol D80. Hydrometallurgy 1996, 41, 45-53. 

The products of the reaction are the following /-butyl-phenyl-ether (TBPE), p-/-butyl-phenol (p-TBP), o-/-butyl-phenol (o-TBP) and 2,4-di-/-butyl-phenol (2,4-DTBP). Compounds adsorbed on the external surface were recovered in methylene chloride (CH2C12) by a soxhlet treatment for 24 hours of the deactivated zeolite sample. The content of the compounds inside the zeolite (coke) was determined after dissolution, in 40 % HF at room temperature, of the catalyst recoved after 5 min, 45 min, 5h and 7.5 h extraction by CH2C12 then followed. The composition of soluble coke was investigated by analysis GC-MS. The procedure is reported in detail elsewhere [10]. 

Oeschger, H., Stauffer, B., Bucher, P., Loosli, H. H., Extraction of Gases and Dissolved and Particulate Matter From Ice in Deep Boreholes, Proc. Grenoble Symposium, 1975, IAHS, Publ. No. 118, 1977, 307-311. 

Potassium. From the standard graph determine the number of pg mM of potassium in the sample, subtract the blank value and multiply the difference by 5 (initial extraction ratio). The result is the number of mg h extractable potassium in the air-dry soil. Include any extra dilution factors, and, if required, convert to oven-dry soil using the appropriate factor, as in Method... 

Figure 4. Infrared spectra of kraft lignin, Indulin AT (D), and the precipitates collected in the first trap (at 1 bar) after methylamine extraction of Indulin AT (C), methylamine extraction of red spruce (B), and ammonia extraction of red spruce (A). Extraction conditions 2 h extraction at 185 ° C, 275 bar, and 1 g/min solvent flow rate.

Modified Parfait Protocol. Teflon adsorbents were cleaned by 24-h extraction with acetone in a Soxhlet apparatus and stored in acetone. Cleaned Chromosorb T was used to fill a 150-mL silanized addition funnel equipped with a 24-40 male joint on the bottom. A plug of silanized glass wool supported the bed just above the stopcock. The Teflon bed was compressed slightly with a large stirring rod to keep the top of the bed in place while the bed was washed with at least 6 bed volumes (900 mL) of high-purity water. The washed Teflon was kept covered with water and used immediately. 

No photolyses of hexahydro-1,2,4,5-tetrazines have been published. The kinetics of the photodecomposition of 1,3,5-triphenylverdazyl (61) was studied by Soviet authors in various hydrocarbons. The rate depends on the solvent. The excited radical is consumed by H extraction from the solvent and by dissociation at the N—N bond, forming the product 1,3-diphenyl-l,2,4-triazole (138), which catalyzes the decomposition of the verdazyl radical (74IZV2204). The dipole moment of (61) in the excited state is 9 1 D in the ground state it is 2.94 D. 

The only part of H extracting H—) from —h) is that containing /+ , and therefore... 

Nii, S. Masutani, M. Takeuchi, H. Extraction of heavy metal ions using encapsulated extractant-impregnated resins. In Solvent Extraction for the 21st Century (Proceedings of ISEC 99), Vol. 2, eds. M. Cox, M. Hidalgo, and M. Valiente, Society of Chemical Industry, London, 2001, pp. 1279-1283. 

C and THF (20 mL) was added. Sulfur dioxide was then passed through the surface of the mixture for 30 min. The mixture was warmed to ambient temperature and stirred for an additional 15 min. The volatiles were evaporated and to the residue was added water (50 mL) and sodium acetate trihydrate (9.55 g, 70.2 mmol). The solution was cooled on an ice bath and hydroxylamine-O-sulfonic acid (4.62 g, 40.9 mmol) was added. The mixture was stirred at ambient temperature for 1 h, extracted with ethyl acetate (3x100 mL) and the combined extracts were washed with a sodium bicarbonate solution, brine and dried over molecular sieves. Evaporation to dryness gave a viscous liquid (4.93 g), which was chromatographed (silica, eluting with 33% ethyl acetate-hexane) to give a solid 3-(2,5,5-trimethyl-l,3-dioxane-2-yl)-2-thiophenesulfonamide (2.47 g, 72%) m.p. 200°-202°C. 

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