Propanol, immersion

HPTLC plates Silica gel 60 F254 (Merck, Riedel-de-Haen) before application of the samples the layer is immersed in 2-propanol for 12 hours (preferably overnight) for purification purposes and then activated on a hot plate for 60 min at 110°C. 

HPTLC plates Silica gel 60 F254, extra thin layer (Merck) before the samples were applied these were immersed overnight in 2-propanol and then dried for 30 min at 110°C. 

HPTLC plates Silica gel 60 (Merck), that were prewashed by immersing them in 2-propanol overnight and then drying at 110°C for 60 min. Immediately before the first development the HPTLC plates were conditioned for 20 min at 30 % relative humidity, e.g. over sulfuric acid (50 %, g/g). 

HPTLC plates Silica gel F254 (Merck), which had been prewashed before use by complete immersion overnight in 2-propanol and then dried at 110 °C for 30 min. 

HPTLC plates Silica gel 60 F254 (Merck) before applicati the samples the layers were washed by immersing them for 2-propanol, then dried at 110°C for 30 min, before being s over silica gel in a desiccator. When the samples were beir plied the layer above the application zone was covered with a plate to avoid adsorption of moisture from the atmosphei... 

Irradiation Studies. Irradiation of l,3-diphenoxy-2-propanol (3), 0.01 M in acetonitrile, was conducted at 254 nm, utilizing a 2.5-W low pressure Hg immersion lamp (PCQ9G-1, Ultraviolet Products), and at wavelengths longer than 280vnm, utilizing a Hanovia 450-W high-pressure Hg immersion lamp (Type L) and 9700 Corex filter sleeve. Irradiation of 1,3-diphenoxy-2-methyl-2-propanol (5), 0.01 M in acetonitrile, was also conducted at 254 nm. 

To evaluate its capability for refractive index measurement, the fiber FPI device was tested using various liquids including methanol, acetone, and 2-propanol at room temperature. The interference spectra of the device immersed in various liquids are shown in Fig. 7.12 for comparison. The signal intensity dropped when the device was immersed in liquids as a result of the reduced refractive index contrast and thus lowered Fresnel reflections from the cavity endfaces. However, the interference fringes maintained a similar visibility. The spectral distance between the two adjacent valleys also decreased, indicating the increase of refractive index of the medium inside the cavity. Using (7.4), the refractive indices of the liquids were calculated to be nmethanoi = 1 -3283, acetone = 1 -3577, and n2-propanoi = 1.3739, which was close to the commonly accepted values. 

C. N-Hydroxy-4-(p-chlorophenyl)thiazole-2(3H)-thione. O-Ethyl S-[2-oximino-2-(p-chlorophenyl)ethyl]dithiocarbonate (56.0 g, 0.19 mol) is placed in a 500-mL round-bottomed flask that is equipped with a magnetic stir bar. Diethyl ether (120 mL) is added and the slurry is treated at 0°C in small portions with solid anhydrous zinc chloride, ZnClj, 79.1 g, 0.58 mol) at such a rate that the solvent does not boil constantly (Note 8). After the addition is complete, the flask is stoppered with a drying tube (CaCl2) and stirring is continued for 48 hr at 20°C. The reaction mixture turns into a dear, dark brown solution that solidifies toward the end of the reaction. The flask is immersed in an ice bath and treated dropwise with 5.5 M hydrochloric add (140 mL, Note 9). The precipitate dissolves immediately. Stirring is continued for 30 min at 0°C whereupon a tan-colored solid separates. This material is collected by filtration. It is washed with small portions of diethyl ether (total of 110 mL) and dried to afford 39.8 g (86%) of N-hydroxy-4-(p-chlorophenyl)thiazole-2(3H)-thione (Note 10). The crude material is transferred to a 2-L, round-bottomed flask equipped with a reflux condenser. 2-Propanol (760 mL) is added and the reaction mixture is heated to reflux. Once a dear solution is obtained the heat source is immediately removed (Note 11). The solution is allowed to cool to room temperature. Precipitation of N-hydroxy-4-(p-chlorophenyl)thiazole-2(3H)-thione is completed by immersing the flask for 30 min in an acetone-dry ice bath (-78°C). The product is collected by filtration and dried to afford 21.9 g (53.5%) of N-hydroxy-4-(p-chlorophenyl)thiazole-2(3H)-thione as tan crystals (Notes 12,13). 

Thin-layer chromatography of sorbitol has also been reported on silica gel plates impregnated with cupric ion [38]. The plates were impregnated with Cu(II) by immersing them into copper solutions. Developer solutions of distilled water, aqueous ethanol, or aqueous n-propanol resulted in good separation of sucrose and glucose. 

The bath temperature can also be controlled with an immersion cooler that has been found to be practical for temperatures down to about -80°C [23]. Suggested coolant fluids are methanol [5,23] and 2-propanol [11]. High-power coolers for temperatures as low as -100°C are manufactured by FTS Systems, Inc., Stone Ridge, NY. There are many manufacturers of refrigerated baths for less demanding temperatures. 

Capillary is stored with both ends immersed in iso-propanol filled vials UV - window... 

---