Capillary borosilicate

Stainless steel and PTFE capillary Borosilicate glass microreactor PTFE capillary PTEE capillary... 

Irradiation Procedure. Reaction mixtures were prepared at room temperature by transferring desired quantities of reactants from their storage bulbs to the reaction vessel, a 500-cc. spherical borosilicate glass flask attached to the vacuum line by a section of glass capillary tubing and a 4-mm. bore threaded glass valve with a Teflon plug (Fischer and Porter 795-609). Prior to each experiment this vessel was baked under vacuum at 500°C. for 12 or more hours. 

Joints, borosilicate to soda glass, 25 Joints in closed systems, 168 Joints, Pyrex to Phoenix, 25 Joints, tungsten-sealing to Xovar-seal-ing glasses, 24 Joints, Vitreosil, 175 Joints with capillary tube, 69 Junctions, 4 and 5 way, 68... 

Borosilicate glass capillaries for patch pipettes (World Precision Instruments, Sarasota, EL). 

Beside borosilicate and fused silica capillaries, PS/DVB monoliths have been fabricated within the confines of steel and PEEK tubings [52]. In order to increase the hydrophobic character of the supports, a Friedel-Crafts alkylation reaction was used for the attachment of Cig-moieties to the polymer surface. The derivatized material was demonstrated to be more retentive and to provide more efficient peptide separations compared with the original, nonderivatized monolith. 

Because of the fact that organic polymers are known to suffer from swelling or shrinkage on changing the solvent [73,74], the inner wall of the column housings (fused silica capillaries or borosilicate columns) has—prior to polymerization—to be derivatized in order to provide chemical attachment of the monolith rod to the wall. 

FIGURE 1.3 Schematic representation of the silanization procedure of borosilicate or fused silica capillary column inner walls, (a) Surface etching under alkaline conditions, (b) attachment of reactive groups by condensation with silanol, (c) chemical linkage of polymer (PS/DVB considered as example) by free radical polymerization. 

The material of the nebulizer must be highly corrosion resistant. Commonly, the plastic capillary is fixed to a platinum-iridium alloy (90 10) capillary mounted in stainless-steel gas supply inlets. The impact bead is sometime made of a similar alloy or smooth borosilicate glass. 

For both type of microwave reactors, if the reactor is not supplied with a temperature sensor or more likely accurate temperature measurment is prerequisited during an experiment, the fiber-optic temperature sensor is directly applied to the reaction mixture. In order to secure the sensor from harsh chemicals, the sensor is inserted into a capillary that in turn is inserted into the reaction mixture. In such a case, it is strongly advocated to use capillaries that are made of quartz glass and are transparent to microwave irradiation. Any capillary that is made of glass or even borosilicate glass can always slightly absorb microwave energy, in particular, while the reaction mixture does not absorb microwaves efficiently, and in turn lead to failures of fiber-optic thermometer performance. 

For static nanoESI-MS connect the static nanospray source (Protana, Odense, Denmark) to the mass spectrometer and use for each sample to be analyzed a new borosilicate spray capillary (ES380 Medium , PROXEON Biosystems AIS, Odense, Denmark see Note 3). 

A standard leak is a small container that leaks helium at a very slow and specific amount. As mentioned before, helium diffuses through borosilicate glass (or through ceramic or capillary tube). This diffusion is very consistent at any given pressure and temperature. Within the standard leak is a thimble of borosilicate glass (see Fig. 7.62) around which is the stored helium. The helium leak rate var-... 

Aldonitrile acetates of sugars have been applied to their GC analysis in different polysaccharides [442] on LAC-4R-886 polyester stationary phase (190°C)and to the analysis of polyols and aldoses in urine and crystalline lenses [444] on a capillary column of borosilicate glass (60 m X0.3 mm l.D.) coated with SE-30 containing a dispersion of Silanox 101 (temperature programming at l°C/min from 150°C). These derivatives were very stable and a uniform product was formed from every individual substrate. 

In some instances, especially when the studied powder is air or moisture sensitive, it can be placed inside a low absorbing glass capillary (e.g. a borosilicate glass), after which the capillary is sealed. Filling capillaries with powders is usually a tedious process and it requires larger diameter capillaries than those usually used for surface coverage. Furthermore, it may... 

Figure 2.16 Photograph of a 1mm diameter thin walled (10 pm thick) borosilicate glass capillary, glued with melted wax into a brass holder for clamping to a spinner. The sample is a white organic compound, but exposure to an intense X ray beam turns it yellow. This sample was translated between successive data collection scans to avoid radiation damage, resulting in the striped appearance.

---