Ampoule sealing

A sample of the gem-diazide detonated on contact with a hot glass surface during ampoule sealing operations. 

The product, which is about 90% bicyclobutane and 10% cyclobutene, is sufficiently pure for most purposes. The purity of the product can be determined by gas chromatography analysis at room temperature, using a 275-cm.-long column containing 20% /3,/3 -oxydipropionitrile on Chromosorb W (45/60). The retention times are 2.7 and 3.8 minutes for cyclobutene and bicyclobutane, respectively. Bicyclobutane (b.p. 8°) can be stored temporarily in the gas storage bulb as a liquid in a dry ice-acetone bath or for longer periods of time in an ampoule, sealed under vacuum, and stored in a freezer. 

Each hour, also check on three ampoules the length of the ampoules, sealing, particles, break ring presence, or any printing and note down in X and R charts for parenterals. 

If the sample needs to be sealed in an atmosphere of nitrogen, the inlet of the protecting tube is connected to a low-pressure supply of the gas when the syringe or pipette has been withdrawn. When all the air has been displaced the tube may be slowly withdrawn and the ampoule sealed. Filled ampoules containing volatile samples should be thoroughly chilled in a suitable cooling bath... 

The advantage of using a phosphine complex is that it contains no chloride, and the counter-ion is easily decomposed or eliminated. The complex has to be synthesised (not easy or cheap), and nonaqueous solutions are needed, which means that the support must be dehydrated, the solvent dried, and the finished catalyst stored in ampoules sealed under vacuum. 

We had observed that a weak sublimation only occurred in a classical Piper and Polich configuration when using ampoules sealed under vacuum or filled with pure dry hydrogen with the material charge at 1000-1030°C and the top of the ampoule at 950°C. When such gases and gas mixtures as H2+H2O or Ar are introduced in the ampoules, fast transport to the cold point was observed, demonstrating the activator role of theses gases and gas mixtures. 

Parenteral preparations are filled into various types of containers, depending on the nature of the product. Single-dose injections are filled into glass ampoules sealed by fusion or ex tempore into plastic syringes. Multidose injections are delivered in glass vials sealed with rubber closures with mechanical properties suitable for multiple piercing. Concentrates and powders for injections or infusions are also... 

Irradiation. The samples were irradiated with 60Co y-rays at 77 °K. in ampoules sealed at 10"4-10 5 torr. The ampoules were made from Suprasil quartz which on irradiation gave an ESR signal which was very small compared with the intensity of the sample absorption. The dose rate of the radiation source varied within 300-350 krads/hour. The dose was 3.4 Mrads for most of the experiments. The dose dependence of the radical formation was investigated in the dose range 0.02-10 Mrads. 

Put 10 milliliters (ml) of the solution into a 20 ml colorless ampoule, seal it hermetically, and use this as the sample. Separately, put 10 ml of the solution into a 20 ml colourless ampoule, seal it hermetically, wrap in aluminum foil to protect completely from light, and use this as the control. Expose the sample and control to the light source for an appropriate number of hours. After exposure determine the absorbances of the sample (Ax) and the control (A ,) at 400 nm using a 1 centimeter (cm) pathlength. Calculate the change in absorbance, AA = Ax - A0. The length of exposure should be sufficient to ensure a change in absorbance of at least 0.9. 

A glass ampoule sample holder, as described in Chiu (125), is shown in Figure 6,17. Such a sealed sample container has been found to withstand an internal pressure of up to 1800 psi and is suitable to be used as a microreactor to study most chemical reactions. An ampoule holder, constructed from silver or aluminum metal, is used to support the ampoule in the DSC sample chamber. Liquid or solid samples are introduced into the ampoules by a syringe. The ampoule sealing technique has been described elsewhere (126). 

Alternatively, ampoules may be tip-sealed. The ampoule is rotated while being heated in the burners or it is heated by means of a pair of burners, one on each side of the ampoule. Sealing is by fusion of a bead of glass at the tip of the ampoule. 

The product is stored in glass ampoules sealed in vacuum or in glass bottles sealed under nitrogen. 

Since the pure product is very hygroscopic, it is transferred in the absence of moisture and stored in glass ampoules sealed off with a torch. 

Stored in ampoules sealed in an oxygen-free atmosphere at pressures below 1 mm. When so stored, it is stable for some time at room temperature. 

Fig. 264. Distillation of cesium (also rubidium, potassium, sodium). Scale 1 7. In the actual arrangement the ampoules, sealed to tube D, lie in a plane perpendicular to that of the drawing hence, they remain horizontal during the distillation and do not become prematurely filled with liquid cesium. Tube B is likewise not quite coaxial with B but is inclined slightly downward.

Prepolymerized as above One drop of water added, ampoule sealed under reduced pressure 5.7... 

For the catalyst preparation REACHIM vanadium pentoxide, pure for analysis, and POCH antimony trioxide, of the same grade of purity, were used. The grounded mixture of vanadia and antimony trloxide in quartz ampoule sealed without any evacuation was placed in a cool oven, then it was heated slowly up to 973 K for 7 hours, annealed at this temperature for 30 hours and slowly cooled down to room temperature for 10 hours. One part of black powder obtained by this procedure was xidized at 673 K in air atmosphere for 30 hours another onewas reduced at the same temperature in vacuum (10 Torr) for 4 hours. 

Silver powder (0.0545 g, 0.505 mmol), antimony(III) sulfide (0.0285 g, 0.0839 mmol), and ammonium sulfide (0.100 mL, 40 wt%) are added to a quartz ampoule, sealed, and worked up in the same fashion as the procedure described above (98.8% yield based on Ag). 

Copper powder (0.0520 g, 0.818 mmol), antimony(in) suliide (0.0442 g, 0.130 mmol), elemental sulfur (0.0150 g, 0.467 mmol) and calcium chloride (0.0300 g, 0.270 mmol) are added to a quartz ampoule, sealed, and worked up in the same fashion as the procedure above. 0012864813 is obtained ( 67% yield based on Cu for the clusters only) as shiny black polyhedron-shaped crystals that grow together as clusters of crystals. (These clusters can be easily physically separated from the rest of the single crystals on the filter paper with a microspatula.) Occasionally the product is contaminated with small amounts of famatinite ( 038684) that can be easily separated manually because tetrahedrite is shiny black, whereas famatinite has a characteristic bronze sheen. 

Ge-Se glasses were synthesized by introducing the appropriate quantities of germanium (Ge) and selenium (Se) in silica ampoules sealed under vacuum, by further heating this mixture at high temperature, typically between 750 and 950°C, and by subsequent quenching (see ref. 11 for details). The physical and mechanical properties of the studied glasses are reported in Table 2. 

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