Borosilicate glass tubes

Four column systems are available from Amersham Pharmacia Biotech that can be used to pack SEC media for various applications at the laboratory scale. These include C, XK, SR, and HR column systems. All of the laboratory-scale columns are constructed with borosilicate glass tubes. Columns for larger scale process applications include INdEX, BPG, EineLINE, BPSS, and Stack columns. The larger scale columns are constructed to meet stringent validation requirements for the production of biopharmaceuticals. Each of the column types are described. 

As a practical result, the amount of gel to be prepared for a preparative column must exceed the nominal volume of the final column by 10%. For the packing of production-scale columns the maximum pressure rate of the column has to be considered. The large columns consist mostly of borosilicate glass tubes with similar pressure stabilities. For example, a Superformance column with dimensions of 1000 mm in length and 50 mm in width is pressure stable up to 14 bar. Therefore, Fractogel EMD BioSEC should be packed with a... 

For a small amount of material (<0.1 g), the method is simple and easy, using the basic technique of glass blowing. A piece of borosilicate glass tube, 5-6 mm inside diameter and about 30 cm long, is washed and dried in advance (Fig. A.2, (A)). First, one end of the tube is sealed with a narrow flame of a gas-oxygen torch. This is done by heating... 

Heating a mixture of C2B4Hg and xs Fe(CO)5 to 240°C in a borosilicate glass tube with its lower end maintained at 25°C gives two products, namely 7,7,7-(CO)3-... 

Similar results were obtained when TCDD in methanol was exposed to natural sunlight in sealed borosilicate glass tubes or beakers (Figure 3). After about 36 hours exposure, a yellow non-volatile gum was obtained as the sole product by evaporation of the solvent. It showed no UV absorption and did not seem to retain the benzenoid chromophore ... 

The activated charcoal (Columbia JXC) was selected for collection of the analytes. This adsorbent has been reported to give good results for ethylene oxide (9). The sampling tubes consisted of borosilicate glass tubes (15 cm x 4 mm i.d.) packed with 400 mg of the charcoal (300 mg in front section and 100 mg... 

For irradiation at 313 m/, the reactor consisted of a 6- X 2-inch o.d. cylindrical borosilicate glass tube fitted directly to the mass spectrometer by a 24/40 joint. A Hanovia analytical lamp, having an estimated output of 325 watts, was mounted externally alongside the tube. The radiation received by the samples inside the tube was filtered through borosilicate glass and was essentially 313 m/. The ambient temperature within the reactor during irradiation was 25 °C. Some comparative experiments were carried out at 70 °C. with additional heating. There was no detectable temperature effect between 25° and 70°C., and the results reported here are for 25 °C. 

The 0-rings, septums, and glass wool were conditioned at 200 C for 16 hr liefore use.) Inlet liners, 10 X 84 mm, were cut from borosilicate glass tubing. The experimental food blend samples were obtained from the Northern Regional Research Center, Peoria, Ill, The rice samples cane from the USDA rice experiment station in Beaumont, Tex., and the peanuts from the USDA Coastal Plain Experiment Station in Tifton, Ga. 

Organic Solvents and Lipid Solutions. Reagent grade solvents were distilled before use. The lipids were dissolved in chloroform-methanol (85 to 15 v./v.) at a concentration of about 0.5 mg. per ml. and stored in glass-stoppered borosilicate glass tubes for not longer than 5 days at 5°C. Lipid mixtures were freshly prepared from the stock solutions of the individual components. 

Apparatus and Procedure. The conventional microreactor was used to determine catalytic activities. The reactor was a 4 mm id borosilicate glass tubing, directly connected to the dual column gas chromatograph... 

Accurately weigh (and record the weight of) 0.01 to 0.30 g oil or lipid extract sample into a 16 xl25-mm borosilicate glass tube. 

Construct a standard curve by repeating steps 1 to 6 without using oil or lipid extract sample. Instead of the sample, add to a series of 16 x 125-mm borosilicate glass tubes varying aliquots of an iron(III)-chloride standard solution (10 pg/ml), 50 pi of 10 mM xylenol orange solution, and enough 7 3 (v/v) chloroform/methanol solution to a final volume of 10 ml. 

Place 5 mg of dried cell walls or cell-wall fractions (uNrr E3.i) into a scrupulously clean (see Critical Parameters) borosilicate glass tube (in duplicate). Record the exact weight of cell walls or fractions. 

Filter hydrolysate using glass syringe fitted with a Swinney stainless steel 13-mm filter unit and a 0.22- im PTFE filter into a clean borosilicate glass tube. After each sample has been filtered, discard the PTFE filter and wash the syringe and filter unit 6 times in Milli-Q-purified water to ensure there is no carryover from one sample to another. 

Add 1 ml dichloromethane (DCM) to extract the alditol acetates. Vortex to mix (do not cap the tubes, as the glue holding Teflon liners may be soluble in DCM). Allow the phases to separate and transfer the lower DCM phase to a clean borosilicate glass tube using a Pasteur pipet. 

Filter the hydrolysate using glass syringe fitted with aSwinney stainless steel 13-mm filter unit and a 0.22-pm PTFE filter into a clean borosilicate glass tube. 

Add 200 pi of the filtered hydrolysate to a scrupulously clean borosilicate glass tube (see Critical Parameters). 

Prepare a 13-sugar standard control by adding 100 pi of the 13-sugar standard to a clean borosilicate glass tube (allow the standard to thaw and mix well before use), then add 100 pi of Milli-Q-purified water (total volume 200 pi) and 20 pi of 15 M ammonia. Vortex to mix. 

Borosilicate glass tubes and caps 10-ml volumetric flasks 15-ml centrifuge tubes 15-ml borosilicate glass tubes 100°C water bath Spectrophotometer... 

Weigh 5 mg (record exact weight) of cell walls or cell-wall fraction (in duplicate) into borosilicate glass tubes (see unit E3.i for cell wall preparation and cell-wall fractionation). 

For each hydrolysate, set up three 15-ml borosilicate glass tubes. For the reagent control, set up two tubes. Take aliquots of 400 pi from each hydrolysate supernatant and reagent control and place in the respective tubes. 

Plant samples were dried, ground and then redried for four hours at 90 °C before analysis. The dried sample (1 g) was placed in a borosilicate glass tube and digested with 1 ml of a mixed digestion acid (200 ml 72% m/v perchloric acid and 50 ml 68% m/v nitric acid) plus 5 ml redistilled 72% m/v nitric acid and two drops of kerosene to prevent frothing. The tubes were digested for three hours at 130 °C, and then 2 ml of redistilled 20% m/v hydrochloric acid is added when cold. After treatment with sodium borohydride, the solutions are evaluated at the selenium 196 nm resonance line. 

Reactor Dimensions. Borosilicate glass tube, 10-mm. i.d., with 6-mm. o.d. thermocouple well down the center. The catalyst was supported on a sintered-glass disk. The empty tube was tested for catalytic activity and found inactive towards thiophene at temperatures up to 550° C. 

Figure 8 Schematic representation of the pilot scale photocatalytic reactor. Keys (1) UV lamp, (2) distribution heads, (3) borosilicate glass tubes.

Pure hydrides can be obtained in the laboratory by reacting the metal vapor with Hj in contact with a wall and, therefore, in a heterogeneous phase. The apparatus in Fig. 1 is derived from that used to prepare pure hydrides. The reactor is a horizontal borosilicate glass tube, a few cm in diameter the lower portion is heated by a half-cylindrical oven. The T= T, of the metal contained in an Fe or Ni nacelle is lower than the dissociation T of the hydride, so that the hydride covers the metal. The system is not in equilibrium, however, because of the gradient between T, and of the upper wall of the tube (T, > Tj). The hydride layer constantly gives off vapor, which com-... 

Such spirals are very difficult to make freehand and are normally wound on a former. A straight borosilicate glass tube, covered with asbestos paper, can be used as a former, but some difficulty may be experienced when withdrawing this tube from the finished coil. Brass tube formers are easier to withdraw, provided they are quite straight. Spiral winders with a ground taper finish eliminate these difficulties. They are fitted with a wooden handle and a small metal loop which holds the glass tube end securely. 

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