Propanol-Water-Heptane

Table 6.59 n-Propanol-Water-Heptane (19) Table 6.60 n-Propanol-Water-Hexane (19)... 

Reagent 1 5% (v/v) solution of PITC in heptane Reagent 2 1.0 M Quadrol-trifluoroacetic acid buffer in n-propanol water (3 4, v/v) pH 9.0... 

Propanol/M-heptane Water, sulfolane SUicone-coated HF [267, 268]... 

Some of the earUest bonded phase chromatographic separations of triacylglycerols used a stationary phase of hydroxyalkoxypropyl Sep-hadex under low pressure conditions in combination with mobile phases of either acetone-water-heptane (87 13 10) plus 1% pyridine to reduce acid hydrolysis (Curstedt and Sjovall, 1974) or a gradient system of 2-propanol-chloroform-hexane-water (115 2 15 35) and heptane-acetone-rwater (5 15 1) (Lindqvist et al., 1974). In these separations good resolution of Cg to C54 triglycerides was reported... 

On the other hand, both theories have problems for the most polar gases and solids, especially for water and sihca gel systems. For both 2-propanol/water and heptane/water, even though the percentage deviations do not seem that high, especially with lAST, the results are deceptive because the trend of the experimental data with respect to selectivity or the amount adsorbed are not predicted well at aU. 

We see in Fig. 7 that our performance goal, 5000 plates in 5 min, can be rather easily met by using heptane or acetonitrite (t) = 0.4 cP). With more viscous eluents such as CCl (ij = 0.94 cP), water, (ij 1.01 cP), or ethanol (rj 1.1 cP), it becomes difficult and the accomplishment of our goal is practically impossible with more viscous solvents such as propanol (17 = 2 cP) or butanol (tj = 3 cP). The latter solvents, however, are rarely used as eluents in HPLC, but water/ethanol and water/methanol mixiures have viscosities in the 0.5-3 cP range. 

Recent advances in chromatography have made it possible to employ microbore HPLC for the determination of NOC. Its main advantage is that it uses a very low mobile-phase flow (20-100 /rl/min). This might make the TEA compatible with a reversed-phase system. Massey et al. (73), in fact, have successfully used reversed-phase chromatography for the HPLC-TEA determination of V-nitroso-V, 7V -di methylpiperazinium iodide. A 500-mm X 1-mm microbore ODS column and a mobile phase consisting of 0.1 M ammonium heptane-sulfonate in methanol water (70 30) (flow rate 20 /zl/min) was used for the HPLC separation. In another study, Riihl and Reusch (74) used a microbore Spherisorb 3 SW column for HPLC-TEA determination of volatile V-nitrosamines. The mobile phase was a mixture of 2-propanol and n-hexane (2.5 97.5). Further application of such techniques for the determination of various polar NOC, especially A-nitrosamides, in foods is desirable. 

Fig. 11.1. Blind test for the COSMO-RS relative solubility prediction of commercial drugs from Merck Co., Inc. [119] All values are calibrated against the experimental solubility in ethanol. The 14 solvents are water, 1-propanol, 2-propanol, dimethylformamide, ethyl acetate, methanol, heptane, toluene, chlorobenzene, acetone, ethanol, acetonitrile, triethylamine, and 1-butanol.

To a 12 L 3-neck round bottom flask was added isopropyl acetate (6.5 L). The solvent was cooled to 0°C in an ice-water bath and 3-amino-l-propanol (1.14 kg, 15.1 mol) was added in one portion. To this stirring solution, benzyl chloroformate (1.20 kg, 7.03 mol) was added dropwise over 2 hours while maintaining the internal temperature of the flask between 10-15°C. After the addition was complete, the reaction mixture was allowed to stir for an additional 0.3 hour after which time water (3.5 L) was added in one portion. The solution was then partitioned and washed with an additional 2 times 3.5 L of water. The organic layer was dried over potassium carbonate and concentrated to give a solid that was dissolved in excess isopropyl acetate and precipitated from solution by adding the compound to heptane. The solid was filtered under nitrogen to yield 1.20 kg (82%) of N-carbonylbenzyloxy-3-aminopropanol as a colorless solid. 

The mobile phases used in normal-phase chromatography are based on nonpolar hydrocarbons, such as hexane, heptane, or octane, to which is added a small amount of a more polar solvent, such as 2-propanol.5 Solvent selectivity is controlled by the nature of the added solvent. Additives with large dipole moments, such as methylene chloride and 1,2-dichlor-oethane, interact preferentially with solutes that have large dipole moments, such as nitro- compounds, nitriles, amines, and sulfoxides. Good proton donors such as chloroform, m-cresol, and water interact preferentially with basic solutes such as amines and sulfoxides, whereas good proton acceptors such as alcohols, ethers, and amines tend to interact best with hydroxylated molecules such as acids and phenols. A variety of solvents used as mobile phases in normal-phase chromatography are listed in Table 2.2, some of which may need to be stabilized by addition of an antioxidant, such as 3-5% ethanol, because of the propensity for peroxide formation. 

The static mode uses both organic solvents such as toluene [27], methanol [28] or acetone [29] and solvent mixtures (usually in a 1 1 ratio) including dichloromethane-acetone [20,28], acetone-hexane [30,31], heptane-acetone [31], acetone-isohexane [32] or methanol-water [33], The use of mixed solvents as extractants provides improved extraction in terms of expeditiousness and recovery [20,28,30-35] as a result of the solubility parameter for a binary mixture being roughly proportional volumewise to the parameters of its components [36], Thus, in the extraction of Irganox 1010 from polypropylene, the addition of 20% of cyclohexane to 2-propanol doubles the extraction... 

Besides methanol, many other polar and nonpolar modifiers have also been used to successfully improve the separation in SFC. These modifiers include acetone, acetonitrile, acetic acid, butane, butanol, n-butyl chloride, carbon tetrachloride, dioxane, ethanol, formic acid, heptane, hexane, n-hexylamine, methylene chloride, nitromethane, propanol, proprionitrile, tetrahy-drofuran, toluene, triethanolamine, trifluoroacetic acid, trifluoroethanol, trimethyl phosphate, and water. 

Table 19 also indicates some methods of decreasing the interfacial tension between water and heptane. The addition of a small amount of surfactant makes a significant difference. Similarly, ternary azeotropes formed by the addition of small amounts of n-propanol, butoxyethylene glycol, or other polar organics, also produce catalysts with high pore volumes, because the second organic, which contains both lipophilic and hydrophilic entities, can lower the interfacial tension between water and heptane. Some examples of this approach are also shown in Table 19. 

Extraction of water from an aqueous solution of ethanol Extraction of water from solutions of alcohols and acetone Extraction of water from an aqueous solution of ethanol Extraction of water from solutions of ethanol, pyridine Separation of Cs isomers Separation of benzeneM-heptane Extraction of water from an aqueous solution of ethanol Extraction of water from solutions of ethanol, acetic acid Separation of dichloroethane/trichloroethylene mixtures Extraction of water from solutions of ethanol, acetic acid Extraction of water from an aqueous solution of ethanol Extraction of water from an aqueous solution of ethanol Extraction of 1 -propanol, ethanol from an aqueous solution Extraction of water from solutions of ethanol and acetic acid... 

Sample preparation 0.5-1 mL Plasma + 500 jxL 4-8 p,g/mL IS in water + 500 p,L buffer + 4 mL dichloromethane n-propanol 99 1, extract on a rotamixer, centrifuge at 1200 g. Remove the organic layer and evaporate it to dryness under a stream of air at 30°, add 5 drops toluene, evaporate to dryness under a stream of air at 30°, reconstitute the residue in 200 p,L 50 mM triethylamine in MeCN, add 100 p,L 60 mM ethyl chloroformate in MeCN, after 30 s add 100 pL 1 M 1-leucinamide hydrochloride in MeOH containing 1 M triethylamine, after 2 min add 500 pL 250 mM HCl, extract with 4 mL ethyl acetate. Evaporate the organic layer to dryness under a stream of air at 30°, reconstitute the residue with 100 pL MeCN, add 400 pL 10 mM pH 6.5 phosphate buffer, inject a 60 pL aliquot. (Prepare buffer as follows. Neutralize a 1 M solution of tetrabutylammonium sulfate in water with NaOH, wash 5 times with dichloromethane, wash twice with heptane. Prepare a 100 mM pH 9.6 sodium carbonate buffer containing 0.5 M of the neutralized and washed tetrabutylammonium salt.)... 

Octylphenol, nonylphenol in 10 min EKC WATER Waste water treatment effluents and sludges SPE Ci8 spiked sample 25.6-50.8% 25 mmol phosphate, 200 mmol SDS, 900 mmolL butanol, 80 mmolL heptane, 20% propanol (pH 2) UV, 214 nm 50mgL (tested) 45... 

Other studies of the preferential solvation for which information can be derived from KBIs in ternary systems have also been made. The system -heptane -i- ethanol + 1-propanol at 313 K (Zielkiewicz 1995a) showed that ethanol and 1-propanol mix in a random manner in the presence of -heptane with no preferential solvation between these two solvents. The same author studied the solvation of N,N-dimethylformamide (C) in mixtures of water (A) and each of methanol, ethanol, and 1-propanol (B) at 313 K (Zielkiewicz 1995b). At Xc > 0.8 this component was solvated equally by A and B, but at Xc < 0.15 it was preferentially hydrated, that is, solvated by A, except when x > 0.8, where the solvation of C by A and B was random. A,A-dimethylformamide (C) featured also in the studies (Ruckenstein and Shulgin 2001a) of it in aqueous (A) methanol (B). The KBIs in the system n-hexane + 1-hexanol + methyl benzoate were studied at 298 K (Aparicio et al. 2005). They calculated the excess (or deficit) number of molecules of, say. A, around molecules of B in pseudobinary systems at constant mole fraction of C from... 

In the two other techniques, the cation (Zr, Y) sources from alkoxides or alkoxide/acetates were dissolved in organics like butanol and propanol the solutions thus produced were dispersed in suitable oil phases like toluene or heptane, and water added into the dispersion, so as to induce gelation of the cation precursors through hydrolysis-polycondensation. The median particle size after calcination was around 50 pm. 

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