Propanol-Water-Hexane

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

The feed compositions and products of each of these strategic separations remain ill-defined. The unspecified 2-propanol—water mixture, the input to each strategic separation, could be but is not necessarily the original feed composition. The MSA composition (pure hexane in this case) is such that one of the products of the strategic separation is in region II, ie, the strategic separation crosses the distillation boundary. Two opportunistic distillations from... 

Various liquid chromatographic techniques have been frequently employed for the purification of commercial dyes for theoretical studies or for the exact determination of their toxicity and environmental pollution capacity. Thus, several sulphonated azo dyes were purified by using reversed-phase preparative HPLC. The chemical strctures, colour index names and numbers, and molecular masses of the sulphonated azo dyes included in the experiments are listed in Fig. 3.114. In order to determine the non-sulphonated azo dyes impurities, commercial dye samples were extracted with hexane, chloroform and ethyl acetate. Colourization of the organic phase indicated impurities. TLC carried out on silica and ODS stationary phases was also applied to control impurities. Mobile phases were composed of methanol, chloroform, acetone, ACN, 2-propanol, water and 0.1 M sodium sulphate depending on the type of stationary phase. Two ODS columns were employed for the analytical separation of dyes. The parameters of the columns were 150 X 3.9 mm i.d. particle size 4 /jm and 250 X 4.6 mm i.d. particle size 5 //m. Mobile phases consisted of methanol and 0.05 M aqueous ammonium acetate in various volume ratios. The flow rate was 0.9 ml/min and dyes were detected at 254 nm. Preparative separations were carried out in an ODS column (250 X 21.2 mm i.d.) using a flow rate of 13.5 ml/min. The composition of the mobile phases employed for the analytical and preparative separation of dyes is compiled in Table 3.33. 

Urease Soybean AOT, CTAB, Triton X-100, mixed AOT-Triton X-100 detergent free micro emulsions (hexane/iso-propanol/water) Solubilization and catalytic studies [81]... 

F. Rabel and K. Palmer, Am. Lab., August 1992, p. 65.] Between uses, reversed-phase columns can be stored in methanol or in water-organic solvent mixtures that do not contain salts. Normal-phase columns should be stored in 2-propanol or hexane. See also R. E. Majors, The Cleaning and Regeneration of Reversed-Phase HPLC Columns, LCGC 2003,21, 19. 

Procedures for isolation and measurement of lipids in foods include exhaustive Soxhlet extraction with hexane or petroleum ether (AOAC, 1995 see Basic Protocol 1), chloro-form/methanol (Hanson and Olley, 1963 Ambrose, 1969), chloroform/methanol/water (Folch et al., 1957 Bligh and Dyer, 1959 see Basic Protocol 2 and Alternate Protocol 2), acid digestion followed by extraction (see Basic Protocol 4), or, for starchy material, extraction with n-propanol-water (e.g., Vasanthan and Hoover, 1992 see Basic Protocol 3). Each method has its own advantages and disadvantages and successful measurement of lipid content is often dictated by the type of sample and extraction medium employed. Commercial extraction and preparation of edible oils are explained in the literature (Williams, 1997). 

FIGURE 9 Chromatograms of enantiomeric resolution on cellulose triacetate CSPs. (a) /V-Benzoylalanine methyl ester, with hexane-ethanol (80 20, v/v) as the mobile phase, (b) Benzoin with hexane-2-propanol-water (70 27 3, v/v/v) as the mobile phase, (c) Mandelic acid with ethanol as the mobile phase. (From Ref. 9.)... 

More often, the bands are narrow, but not well separated from each other, such as in Fig. 1.I8E. In such case, increasing the selectivity contribution to the resolution is the best way to improve the separation. The selectivity could be improved by changing the components of a binary mobile phase (e.g., acetonitrile-water or tetrahydrofuran-water instead of methanol-water in RPC or dichloromethane-n-hexane instead of 2-propanol-H-hexane in NPC), adjusting the concentration ratio in a ternary or a more complex mobile phase, or by using mobile phase additives inducing specific interactions (e.g.. 

The order of polarities of common mobile phase solvents are water > acetonitrile > methanol > ethanol > tetrahydrofuran > propanol > cyclohexane > hexane. 

Dimorphic crystals, mp 94°. Slight aromatic odor. Tasteless. Soly at 20° (g/100 ml) acetone 74.4 dioxane 65.6 iso. propanol 21 hexane 0.4 benzene 44.4 tolnene 29.4 xylene 18.2 carbon tetrachloride 4.9. Practically insol in water. Slightly sol in petr oils. Stable to oxidizing and reducing agents, acids and alkalies found in spray formulations. LDW orally in mice 2.7 g/kg, L. W, Hazleton et al.. ioc. cit. 

Several other isocratic separations of phospholipids on silica have been reported using mobile phases comprising mixtures of hexane-propanol-water (Geurts van Kessel et al., 1977 Abood et al.,... 

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... 

Figure 2 Effects of the concentration of 2-propanol,

The chromatogram shown in Fig. 3 was the first separation profile of oligomeric procyanidins by HSCCC using a two-phase solvent system. In recent times, other hydrophilic solvent systems, such as hexane/methyl acetate/acetonitrile/ water three-phase system,methyl terf-butyl ether/l-buta-noFacetonitrile/water two-phase systems,and ethyl acet-ate/1-butanol (or 2-propanol)/water two-phase systems, were also applied to HSCCC separations of other proantho-cyanidins and/or related polyphenolic oligomers. 

A partition of the transparent isotropic water-in-oil type solubilization area has been proposed as well by Smith and others (20,21) who investigated the phase and structural behavior of oil-continuous systems composed of water, hexane, 2-propanol, with or without addition of hexadecyltrimethylammonium bromide or perchlorate. The techniques used were conductometry, ultracentrifugation and, later, NMR. Smith and coworkers (20) put into evidence kinks on conductivity curves as the system composition was varied by increasing 2-propanol content. Plotting in the phase diagram... 

Analysis of ethoxylated fatty acids using a column (250 x 4.6 mm i.d.) of Nucleosil DIOL with hexane/iso-propanol/water/acetic acid (105 95 10 1 by volume) is described in [28]. 

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