N-Hexane solution

The adsorption of stearic acid from n-hexane solution on a sample of steel powder is measured with the following results ... 

Adventitious water is responsible for the formation of the dimeric hydroxo complex 31 obtained by reaction of AuCb with 1,4-dilithiotetraphenylbutadiene in ether solution [97[. The hydroxo-bridged complex [Au(C6H4N02-2)2( i-0H)[2 (32) was obtained either by reaction of Na[Au(C6H4N02-2)2(0Ph)2] with traces of water in CH2Cl2/n-hexane solution or by treatment of the dichloroaurated complex with NaOH [98[. The crystal structure of 32 2Et20 shows that it is a centrosymmetric... 

The aqueous layer (CNP-NH2 layer) collected by liquid-liquid partitioning is transferred into a separatory funnel containing 20 mL of 4 M KOH aqueous solution and 100 mL of n-hexane, and shaken vigorously for 5 min. The n-hexane layer is collected. A further 100 mL of n-hexane are added to the aqueous layer and shaken again. The n-hexane layers are collected, dried with ca 50 g of anhydrous Na2S04, concentrated to dryness carefully, and n-hexane solution of the residue is prepared for GC analysis. 

Second cleanup Transfer the n-hexane solution into a Florisil cartridge preconditioned with 5 mL of n-hexane and elute thenylchlor with 10 mL of acetone-n-hexane (1 9, v/v). Concentrate the eluate to dryness by rotary evaporation at 40 °C and dissolve the residue in 5 ml of acetone for GC analysis. 

Transfer the n-hexane solution into a glass column packed with 5 g of Florisil saturated with n-hexane. Rinse the column, first with 2mL of n-hexane and then with 50 mL... 

For imidacloprid, the combined Altrates are concentrated with a rotary evaporator. The Anal residue is dissolved in 5 mL of n-hexane and applied to a silica gel cartridge, preconditioned with 5 mL of n-hexane. The n-hexane solution is transferred into the carAidge, which is rinsed with 5mL of n-hexane-ethyl acetate (1 1, v/v) and eluted with 8 mL of ethyl acetate. Further cleanup could be carried out using a Florisil carAidge, if needed. The imidacloprid residue in 4 mL of n-hexane-acetone (13 7, v/v) is eluted with 8 mL of n-hexane-acetone (2 3, v/v). The eluate is concentrated under vacuum on a rotary evaporator at 40 °C. The residue obtained is dissolved in a suitable volume of water-acetoniAile (4 1, v/v) and analyzed by HPLC (270 nm). ... 

Add 0.2 mL of pyridine and 0.1 mL of acetic anhydride to the n-hexane solution for the acetylation of p-OH-buprofezin. Keep the mixture at ambient temperature overnight. Wash the reaction mixture with lOmL of the distilled water twice and collect the n-hexane phase for GC/NPD analyses. 

A sintered glass funnel was packed with 2 cm Celite , 1 cm silica gel and 3 cm sand. The n-hexane solution was carefully filtered through this packed funnel without disturbing the packing material. The filtration was completed by rinsing the packing with diethyl ether (100 mL). 

The elution volumes of polystyrene and benzene in the size-exclusion mode were 0.98 and 1.78 ml, respectively (Figure 1.4A). This means that separations by molecular size can be achieved between 0.98 and 1.78 ml in this system. In the normal phase mode the elution volumes of octylbenzene and benzene were 1.98 and 2.08 ml, respectively, in n-hexane solution (Figure 1.4B). This type of chromatography is called adsorption or non-aqueous reversed-phase liquid chromatography. These are adsorption liquid chromatography and non-aqueous reversed-phase liquid chromatography. The elution order of the alkylbenzenes in the reversed-phase mode using acetonitrile was reversed... 

Photolytic. Synthetic air containing gaseous nitrous acid and toluene exposed to artificial sunlight (Z = 300-450 nm) yielded methyl nitrate, peroxyacetal nitrate, and a nitro aromatic compound tentatively identified as a nitrophenol or nitrocresol (Cox et al., 1980). A n-hexane solution containing toluene and spread as a thin film (4 mm) on cold water (10 °C) was irradiated by a mercury medium pressure lamp. In 3 h, 26% of the toluene photooxidized into benzaldehyde. 

Photolytic. A n-hexane solution containing /n-xylene and spread as a thin film (4 mm) on cold water (10 °C) was irradiated by a mercury medium pressure lamp. In 3 h, 18.5% of the p-xylene photooxidized into p-methylbenzaldehyde, p-benzyl alcohol, p-benzoic acid, and p-methylacetophenone (Moza and Feicht, 1989). Glyoxal and methylglyoxal were produced from the photooxidation of p-xylene by OH radicals in air at 25 °C (Tuazon et al., 1986a). The rate constant for the reaction of p-xylene and OH radicals at room temperature was 1.22 x lO " cmVmolecule-sec (Hansen et al., 1975). A rate constant of 7.45 x 10 L/molecule-sec was reported for the reaction of p-xylene with OH radicals in the gas phase (Darnall et al, 1976). Similarly, a room temperature rate constant of 1.41 x 10 " cm /molecule-sec was reported for the vapor-phase reaction of p-xylene with OH radicals (Atkinson, 1985). At 25 °C, a rate constant of 1.29 x lO " cmVmolecule-sec was reported for the same reaction (Ohta and Ohyama, 1985). 

MOBILE PHASE 5% ETHYL ACETATE in n-HEXANE SOLUTE BENZYL ACETATE... 

Fig, 2-6. Vapor pressures of n-hexane. Solution to Example 2-1. (Data from Stull, Ind. and Eng. Chem., 39, 517, 1947.)... 

Catalytic Experiments. Activities were performed in a 1 liter Parr reactor. A typical experiment was performed as follows at a temperature of 100 °C, 100 mg of the catalyst and 1.5 /. wt of (-)-carvone (Aldrich) in n-hexane solution (100 ml) were Introduced in a high pressure Parr reactor equipped with mechanical stirring and automatic temperature control. Before introducing the hydrogen the system was purged 2 or 3 times with Nz> The total hydrogen pressure was 21 atm. The reaction products were analysed by gas chromatography. NMR and Mass Spectrometry and identified as unreacted carvone, carvotanacetone, carvomenthone and three carvomenthol stereoisomers (axial-equatorial, equatorial-equatorial and equatorial-axial). 

Inject in duplicate up to 2 pi n-hexane solution into the GC. Perform GLC using the following analytical conditions ... 

The TMS ether derivative should be kept in a desiccator until analyzed because it is very susceptible to moisture and hydrolyzes easily. Excess amounts of pyridine usually result in a large and tailing peak on a chromatogram and interfere with the baseline separation of the cholesterol peak. It is therefore recommended to evaporate pyridine under a nitrogen stream and to dissolve the residue in n-hexane. Excess silylating agents usually produce a white residue in the resulting n-hexane solution. Microfiltration prior to GC injection is recommended. 

Butyllithium in pentane was purchased from Alfa Products, Morton/Thiokol Inc. and was titrated by the method of Gilman and Cartledge.23 The checkers used a 1.56 N hexane solution purchased from Mitsuwa Chemical Co. after titration by th Kofron-Baclawski procedure.215... 

Fig. 2.25. Quenching effect on the short-wavelength FB fluorescence band of two different TICT state-forming compounds by adding traces of a polar solvent P to a nonpolar solution. Successive spectra correspond to repeated addition of small amounts of n-butyronitrile to initially 50 mL n-hexane solution, 5 x 10 6M/L. Note the strong difference in response observed for the two solutes.

The electronic absorption spectra were recorded on a Shimadzu UV160A spectrophotometer in n-hexane solutions. 

Exactly the same procedure as described in Section 8.2.2 was repeated with the variant to replace 15 mL of HC1 with 15 mL of DC1 (37%). In such way the deuter-ated derivative C60D18 was obtained in n-hexane solution and subsequently irradiated by UV photons under He. 

When decacarbonyldimanganese(O) (112) is irradiated photochemically at 253 K with 1,3-butadiene (la) in n-hexane solution [Eq. (63)], four dinuclear reaction products are observed by analytical HPL chromatography (169,170). After a short period of irradiation, /r->j3 1 -2-butene-1 -diylenneacar-bonyldimanganese (113a) is the predominate reaction product. Prolonged... 

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