Quartz flasks

Incubation and Degradation Measurements. Radiolabeled or unlabeled compounds were dissolved in acetone and added to 60 ml of estuarine or phosphate-buffered distilled water (pH 7.7 0.2 16 nlM) in 150 ml quartz flasks (Quartz Scientific, Inc.). Acetone was at a final concentration of 1 x 10 and there was no photosensitization of the compounds by acetone in distilled water. These flasks allow more than 852 transmission of light of wavelength longer than 260 nm. Approximately 0.1 ci of the selected compound was added to each flask. The final concentration of each compound in the flasks was adjusted to 25 pg L by the addition of unlabeled compound. 

Charcoal is generally satisfactorily activated by heating gently to red heat in a crucible or quartz beaker in a muffle furnace, finally allowing to cool under an inert atmosphere in a desiccator. Good commercial activated charcoal is made from wood, e.g. Norit (from Birch wood), Darco and Nuchar. If the cost is important then the cheaper animal charcoal (bone charcoal) can be used. However, this charcoal contains calcium phosphate and other calcium salts and cannot be used with acidic materials. In this case the charcoal is boiled with dilute hydrochloric acid (1 1 by volume) for 2-3h, diluted with distilled water and filtered through a fine grade paper on a Buchner flask, washed with distilled water until the filtrate is almost neutral, and dried first in air then in a vacuum, and activated as above. To improve the porosity, charcoal columns are usually prepared in admixture with diatomaceous earth. 

Figure 1. A, Dewar flask B, sintered glass filter C, metal cooling coil D, water inlet E, water outlet F, reaction vessel < , quartz immersion well /f, pyrex filter /, lamp ...

B Immersion well (quartz or pyrex), fitted with inlet (a) and outlet b) for cooling liquid (water or filter solution), and with ground joint (c) to C Reaction flask, fitted with gas inlet d) and outlet (e adapted to hold, e.g., a reflux condenser). 

Nonyl aldehyde (32.66 g, 0.23 mol) and furan (200 mL, 187.2 g, 2.75 mol) were mixed in a 250-mL photolysis flask equipped with a quartz immersion well containing a Vycor filter and a 450-W Hanovia Lamp. The system was kept at -20° C with an isopropyl alcohol bath cooled by a Cryocool Immersion Cooler (CClOO). Nitrogen was bubbled throughout the duration of the reaction, and the solution was stirred vigorously. Additional furan (150 mL, 140.4 g, 2.06 mol) was added during the course of the reaction. TLC analysis indicated completion of the reaction after 20 h. After evaporation of excess furan and NMR analysis of the resultant oil (48.70 g, ca. 100%) indicated the desired photoadduct had been formed, without contamination from unreacted nonyl aldehyde. 

Fig.4.3. Experimental arrangement for investigation of pyrolysis of molecules by the method of semiconductor sensors 1 - reaction vessel, 2 - quartz slab with a ZnO film (sensor), 3 - filter, 4 - contacts, 5 - incandescent filament, 6 - thermocouple, 7 - cell with a substance, 8 - lamp - manometer, 9 - pin, 10 - flask, 11 - sealing bulkhead, 12 - trap, 13 - thermostat.

Interaction is violent and may be explosive, even with ice, oxygen being evolved [1]. Part of the water dropped into a flask of the gas was expelled by the violent reaction ensuing [2], An analytical procedure, involving absorption of chlorine trifluoride into 10% sodium hydroxide solution from the open capillary neck of a quartz ampoule to avoid explosion, was described [3], Inadvertent collection of chlorine trifluoride and ice in a cryogenic trap led to a small but violent explosion when the trap began to warm up overnight [4],... 

When the hydrolysis is complete carefully wash out the condenser with 10-12 c.c. of water. Then distil up to 5 c.c. of liquid into a small conical quartz flask. Use the condenser in the downward position and if necessary add a few boiling capillaries to the liquid in the flask. Repeat the distillation three more times, each time adding 7 c.c. of water. Test the distillate (volume about 20 c.c.) with some barium chloride for sulphuric acid (none should be present), boil for seven to eight seconds and titrate at once with 0-033 N sodium hydroxide solution 1 from a micro-burette having 0-02 c.c. scale-divisions. Use phenolphthalein as indicator and continue the titration until the colour becomes just pink and remains so for a few seconds. For the second titration distil 2 x 7 or 3 x 7 c.c. and for the third and fourth titrations only about 7 c.c. on each occasion. 

In a solution containing oxygen, photolysis yields a mixture of 6,12-, 1,6-, and 3,6-diones. Nitration by nitrogen dioxide forms 6-nitro-, 1-nitro-, and 3-nitrobenzo[a]pyrene. When benzo [a] pyrene in methanol (1 g/L) was irradiated at 254 nm in a quartz flask for 1 h, the solution turned pale yellow. After 2 h, the solution turned yellow and back to clear after 4 h of irradiation. After 4 h, 99.67% of benzo[a]pyrene was converted to polar compounds. One of these compounds was identified as a methoxylated benzo[a]pyrene (Lu et al, 1977). A carbon dioxide yield of 26.5% was achieved when benzo [a] pyrene adsorbed on silica gel was irradiated with light (A, >290 nm) for 17 h (Freitag et al, 1985). 

Photooxidation of chlorobenzene in air containing nitric oxide in a Pyrex glass vessel and a quartz vessel gave 3-chloronitrobenzene, 2-chloro-6-nitrophenol, 2-chloro-4-nitrophenol, 4-chloro-2-nitro-phenol, 4-nitrophenol, 3-chloro-4-nitrophenol, 3-chloro-6-nitrophenol, and 3-chloro-2-nitrophenol (Kanno and Nojima, 1979). A carbon dioxide yield of 18.5% was achieved when chlorobenzene adsorbed on silica gel was irradiated with light (A. >290 nm) for 17 h. The sunlight irradiation of chlorobenzene (20 g) in a 100-mL borosilicate glass-stoppered Erlenmeyer flask for 28 d yielded 1,060 ppm monochlorobiphenyl (Uyeta et al., 1976). 

Flasks, 250 ml, conical with ground joint - silica (quartz), or soda glass. 

HNL and UVL direct effect on human erythrocytes was studied using fresh donor blood. The blood was placed into a quartz flask, and the end of the waveguide... 

The reaction apparatus (Figure 1) requires a tubular quartz flask with two side arms and a large ground-glass joint at the top to accommodate the water-cooled UV lamp. 

Photolysis Reactors and Ultraviolet Sources. For 253.7-m/ irradiation, a modified irradiation apparatus purchased from Delmar Co. was used. The reactor was a 2-necked, 500-ml., round-bottomed flask. One neck was an O-ring joint, and the other was a 24/40 joint. A 4- X 1-inch coiled low pressure mercury quartz lamp was placed inside the flask through the O-ring neck, and the joint was sealed with removable O-rings. The reactor was connected directly to the mass spectrometer by the 24/40 joint. The samples were placed inside the flask and irradiated internally. The O-ring was shielded from direct radiation so as not to induce degradation. The estimated output of the lamp was 30 watts, and the ambient temperature within the reactor during irradiation was 70°C. 

G. P. Baxter and F. B. Coffin 4 used this process for preparing hydrobromic acid for their work on at. wt. The hydrobromic acid was condensed in water contained in a cooled flask. In order to remove iodine, the soln. was diluted with water, and twice boiled with a little free bromine. A small quantity of potassium permanganate added, and the bromine set free was expelled by boiling. The acid was finally distilled with the aid of a quartz condenser, and the first third rejected. 

Preparation. Assemble an apparatus as shown in Fig. 109. Mix 2 g of dry quartz sand with 2 g of calcium fluoride. Transfer the mixture into a Wurtz flask and add 15 ml of a 96% sulphuric acid solution. Close the flask with a stopper. The funnel must touch the surface of the water in the beaker. Heat the flask. What do you... 

Preparation of Aluminium Chloride in a Fluidized Bed. Assemble an apparatus as shown in Fig. 121. Place 25 g of dry aluminium oxide onto porous chamotte partition 2 of quartz reactor 1 and 200-250 ml of carbon tetrachloride into flask 4. Pass a stream of dry nitrogen into the apparatus via tube 3 at such a rate that a flame of the metal oxide appears at a distance of 30-50 mm from the edge of the horizontal bend of the reactor. 

Cool the beads in a desiccator and rapidly transfer them into the quartz tube of a chlorination apparatus (see Fig. 111). Again dry the mixture in a stream of clean and dry carbon dioxide at 500-600 °C until steam stops condensing at the quartz tube outlet. After removal of the moisture, connect a preliminarily weighed receiver— a Wurtz flask or a Wurtz test tube—to the reaction tube instead of flask 3. Displace the carbon dioxide with a stream of dry chlorine and, maintaining the furnace temperature at about 600 °C, pass a strong chlorine stream through the system. What happens Write the equation of the reaction. 

For simple distillations a Claisen flask (see, for example, Quickfit and Quartz Ltd cataloque of interchangeable laboratory glassware, Kontes Glass Co, Vineland, New Jersey, cat.no TG-15, Normschiff, Wertheim, Germany, Embell Scientific, Murwillumbah, NSW 2484, Australia) is often used. This flask is, essentially, a round-bottomed flask to the neck of which is joined another neck carrying a side arm. This second neck is sometimes extended so as to form a Vigreux column. 

---