W-Butanol-water

If the above solvent search reaches the solvent system of n-hexane/methanol/water (2 1 1), which is suitable for the most hydrophobic compounds, and a more hydro-phobic solvent system is required, one may reduce the amount of water from the above solvent system and/or replace methanol with ethanol. Some useful solvent systems for the extremely hydrophobic compounds are M-hexane/ethanol/water (6 5 2) and w-hexane/methanol (2 1). On the other hand, if the solvent search reaches the solvent systems of w-butanol/water or ferf-butyl methyl ether/butanol/acetonitorile/water (2 2 1 5), which are suitable for the most hydrophilic compounds, and a still more hydrophilic solvent system is required, the above solvent system may be modified by the addition of acid or salt trifluoroacetic acid (TFA) or ammonium acetate has been successfully used. 

We use the w-butanol-water system in this chapter as an example of this type of binary heterogeneous azeotropic system. A straight-forward two-column distillation system can be used to easily achieve high-purity products. A simple control structure is developed that is capable of handling very large disturbances in throughput and feed composition. The control... 

A simple control stmcture has been developed and demonstrated to be remarkably robust for the separation of the binary heterogeneous azeotropic w-butanol-water system. The process configuration consists of two stripping columns, a decanter, and a single condenser. A tray temperature is controlled in each column. Very large disturbances in feed flowrate and feed composition are effectively handled with product compositions maintamed close to the desired values. 

Standard-grade silica gel is recommended since the trace metals present aid the separation of peonidin and malvidin from cyanidin and delphinidin (Harbome, 1998). Preparative TLC of anthocyanins using 20 X 20 cm chromatoplates with 1-mm layers of a mixture of 2/3 silica gel (adsorbosil-2) and 1 /3 cellulose powder (MN-300, gypsum free) was described by Asen (1965). He employed the following solvent systems to purify milligram quantities of anthocyanins from plant tissues w-butanol/water (1 1), water/HCl/formic acid (8 4 1), 1 % HCl, and acetone/0.5 N HCl (1 3). Table 5.2 lists Rf values of some common anthocyanidins on microcrystalline cellulose (Strack and Wray, 1989). The simultaneous analysis of anthocyanidins and anthocyanins on cellulose layers using a solvent system of concentrated HCl/formic acid/water (24.9 23.7 51.4) has been demonstrated by Andersen and Francis (1985). 

The order of elution is acetone and methyl isobutyl ketone, isopropyl alcohol, w-butanol, water. 

C) Mixed solvent. A well-shaken mixture of 20 ml. of redistilled w-butanol, 9-5 ml. of water, and 5-5 ml. of 95% ethanol. 

FIGURE 10.5 Elution profile on OH-B12 treated by microwave heating for 6 min during silica gel 60 column chromatography. Fifty milliliters of the treated OH-B12 solution (5 mmol/1) was evaporated to dryness and dissolved in a small amount of w-butanol/2-pro-panol/water (10 7 10, v/v) as a solvent. The concentrated solution was put on a column (1.4 X 15.0 cm) of silica gel 60 equilibrated with the same solvent and eluted with the same solvent in the dark. The eluate was collected at 4.0 ml with a fraction collector. Fractions I to V were pooled, evaporated to dryness, dissolved with a small amount of distilled water, and analyzed with silica gel TLC. Inset represents the mobile pattern of the OH-B12 degradation products of fractions I to V on the TLC plate. Data are typical, taken from one of five experiments. (Reprinted with permission from Watanabe, F. et al., J. Agric. Food Chem., 46, 5177-5180, 1998. Copyright (1998) American Chemical Society.)... 

Alcohols are hydroxylated alkyl-compounds (R-OH) which are neutral in reaction due to their unionizable (OH) group (e.g., methanol, ethanol, isopropanol, and w-butanol). The hydroxyl of alcohols can displace water molecules in the primary hydration shell of cations adsorbed onto soil-solid and sediment-solid clay particles. The water molecule displacement depends mainly on the polarizing power of the cation. The other adsorption mechanisms of alcohol hydroxyl groups are through hydrogen bonding and cation-dipole interactions [19,65],... 

To a flask containing 405 gm (5.47 moles) of w-butanol is added 25.3 gm (1.1 gm-atom) of sodium metal in small portions. After the reaction is complete, 154.0 (1.0 mole) of A V-di-w-butylcyanamide is added with sufficient benzene to keep the refluxing pot temperature at approximately 100°C. The mixture is refluxed for 3 hr, glacial acetic acid is added to neutralize the base, the mixture is washed with water, the organic layer is separated, dried, and then distilled to afford 194.0 gm (85 %), b.p. 117°C (2.0 mm), ng 1.4500, df 0.8871. 

We conclude this section with some brief comments on the cosolvent effects of partially miscible organic solvents (PMOSs). These solvents include very polar liquids such as w-butanol, w-butanone, w-pentanol, or o-cresol, but also nonpolar organic compounds such as benzene, toluene, or halogenated methanes, ethanes, and ethenes. For the polar PMOS, a similar effect as for the CMOS can be observed that is, these solvents decrease the activity coefficient of an organic solute when added to pure water or to a CMOS/water mixture (Pinal et al., 1990 Pinal et al., 1991 Li and Andren, 1994). For the less polar PMOS there is not enough data available to draw any general conclusions. 

Fractions H and /. Paper chromatography indicated that these two fractions were identical except for a few minor spots. The combined fractions were purified by cellulose column chromatography with the upper layer of 4 1 5 w-butanol-ethanol-water as the developer. Over 95% of the combined fraction was recovered as pure oxalic acid. 

To extract excess reactant, add to the reaction medium, 3 ml of w-butanol and 3 ml of water. Mix well. Centrifuge the mixture to separate the two phases. Discard the upper yellow layer. Repeat the extraction process several times, then dry the remaining solution containing activated oligo using a lyophilizer or a rotary evaporator. The PDITC-activated DNA is stable in a dry state. 

Aniline phthalate An aniline (1 g)/o-phthahc acid (1.5 g) in w-butanol (100 ml) (saturated with water) is sprayed on the plate, which is then heated at 105°C (10 min), yielding a variety of colors. 

Rump [17] has described a cellulose thin layer method for the detection of phenolic acids such as iw-hydroxybenzoic acid, iw-hydroxyphenylacetic acid and m-hydroxyphenylpropionic acid, in water samples suspected to be contaminated with liquid manure. The phenolic acid is extracted with ethyl acetate from a volume of acidified sample equalling lmg of oxygen consumed (measured with potassium permanganate). The ethyl acetate is evaporated and the residue dissolved in ethanol. After spotting of a lpm aliquot on a cellulose plate the chromatogram is developed by capillary ascent with the solvent n-propanol-w-butanol-25% NH3-water (4 4 1 1 by vol). The solvent front is allowed to advance 10cm. The air-dried plate is sprayed with a diazotised p-nitroanilinc reagent to make the phenolic acids visible. 

Mobile phase for paper chromatography—Mix 1.8 liters of w-butanol, 450 ml of glacial acetic acid, and 750 ml of water. Store tightly covered in a dark bottle at room temperature. 

We only give basic directions for the choice of a solvent system. If the polarities of the solutes are known, the classification established by Ito [1] can be taken as a first approach. He classified the solvent systems into three groups, according to their suitability for apolar molecules ( apolar systems), for intermediary polarity molecules ( intermediary system), and for polar molecules ( polar system). The molecule must have a high solubility in one of the two immiscible solvents. The addition of a third solvent enables a better adjustment of the partition coefficients. When the polarities of the solutes are not known. Oka s [8] approach uses mixtures of n-hexane (HEX), ethyl acetate (EtOAc), n-butanol (n-ButOH), methanol (MeOH), and water (W) ranging from the HEX-MeOH-W, 2 1 1 (v/v/v) to the n-BuOH-W, 1 1 (v/v) systems and mixtures of chloroform, methanol, and water. These solvent series cover a wide range of hydrophobicities from the nonpolar n-hexane-methanol-water system to the polar n-butanol-water system. Moreover, all these solvent systems are volatile and yield a desirable two-phase volume ratio of about 1. The solvent system leading to partition coefficients close to the unit value will be selected. 

Thin layer chromatography is used for the analysis of free amino acids from sanguine plasma in different progression states in maladies diabetes, renal syndrome, and hepatic cirrhosis.Elution was performed on cellulose plates and the densitometry was achieved with a photodensitometer (Shimadzu CS-9000) at 575 nm. In the case of hepatic cirrhosis, a better resolution was obtained. A mixture of w-butanol-acetone-acetic acid-water (35 35 7 23 vol/vol/vol/vol) was used as the mobile phase. 

In each solvent series,the partition coefficient of the sample can be finely adjusted by modifying the volume ratio of the components. The first series covers a broad range in both hydrophobicity and polarity continuously from M-hexane/methanol/water to n-butanol/water. The second series of chloroform/methanol/water provides moderate hydrophobicity and the third series of ferf-butyl methyl ether/w-butanol/acetonitorile/water is suitable for hydrophilic compounds. Most of these two-phase solvent systems provide near 1 1 volume ratios of the upper/lower phases, together with the reasonable range of settling times in 30 sec or less, so that they can be efficiently applied to HSCCC and other centrifugal CCC schemes. 

T.W. Kim, F. Kleitz, B. Paul, and R. Ryoo, MCM-48-like Large Mesoporous Silicas with Tailored Pore Structure Facile Synthesis Domain in a Ternary Triblock Copolymer-Butanol-Water System. J. Am. Chem. Soc., 2005, 127, 7601-7610. 

Aoudia, M., Rodgers, M.A.J. and Wade, W.H. (1991) Light scattering and fluorescence studies of o/w microemulsion The sodium 4-dodecylbenzenesulfonate-butanol-water-NaCl-Octane system. /. Coll. Int. Sci., 144, 353-362. 

Fine needles from merhanol or acetone, mp 243. Recrystallization from water yields the hydrate, C12H.3NjO4.HjO, mp 239-243. [ ](> -45.7 (e = 1.05 in 0.11V HCI). uv max (HjO) 230, 277 nm (E 400. 548). Soluble in acetic acid, acidic solns. Moderately so] in methanol, ethanol, acetone, dioxane, butanol, water, ether. Practically insol in chloroform, ethyl acetate, petr ether. LD (W in mice 10-20 mg/kg. c., Nishimura et al, loc, cit. 

In this study, the effects of the water content on the enzyme-catalyzed methanolysis of rapeseed oil was investigated via the addition of a small quantity of water to the reaction solution of methanol and rapeseed oil as substrates, tert-butanol as a solvent, and Novozym 435 as the enzyme. The reaction was conducted with the addition of water in a range from 0 to 10% (w/w) based on the weight of rapeseed oil, with a constant temperature of 40 °C and a reaction time of 24h. As is shown in Fig. 4, the highest conversion was approximately 76.1% at a water content of 1% (w/w). The conversion increased in a linear fashion with increases in the water content within a range of below 1% (w/w). At water content values in excess of 1% (w/w), the conversion was reduced in a linear fashion. 

Administration of ethanol, methanol, and w-butanol extracts but not a water extract of gotu kola to rats at doses of 28 ml/kg daily for 14 days inhibited in vitro platelet reactivity. The ethanol extract also inhibited dynamic coagulation (Satake et al. 2007). 

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