Stainless steel capillaries

A sample contained in a dropping funnel at 25°C exploded forcefully. Though not sensitive to mechanical shock, it could be detonated by a hot wire when unconfined, or if rapidly heated to 220°C when confined in a stainless steel capillary. 

Fig. 11.2. Schematic of a thermospray interface. A cartridge heater B copper block brazed to stainless steel capillary C capillary D copper tube E ion lenses E quadrupole mass analyzer G line to rotary vane pump H ion exit aperture J source heater. Reproduced from Ref. [30] by permission. American Chemical Society, 1983.

In order to satisfy the spedflcation outlined above, a special interface was developed. TTie detailed design of this interface, the transport system, and over-pressure system have been the subject of a previous pubhcation and a patent application [24]. The system devised for the interface is based on modifications to an injection system presented by Heilbronner et al. [2S] for preparative gas chromatography. A commercial version of the preparative unit was developed by Boer [26]. In this appfication. samples are monitored into the injection vessel which is connected to the gas chromatographic column by a length of stainless steel capillary tubing. 

In order to extract small fluid samples from the reaction cell at high temperatures, a capillary with a tip of sintered alumina, can be introduced sidewise into the center of the reaction cell. The samples pass into a section of stainless steel capillary between two high pressure valves mounted on a heated metal block. The capillary section serves as a pipette from which liquid and gaseous components can be extracted for analysis. Another method is, to use a small spindle press. By turning it back very slowly, samples can be sucked out steadily from the reaction cell. 

Figure 3.38 — Integrated flow-through sensors. (A) With electrochemical generation of the luminescent reagent. The flow stream path follows the line between the analyte inlet and the outlet to waste. (B) With immobilization of a phosphor (length, 3 cm internal diameter, 2 mm) 1 immobilized phosphor 2 CFG 3 quartz wool plug 4 KEL-F caps 5 hand-tightened screw 6 stainless steel capillaries. (C) Sensor based on reflectance measurements. The sensor membrane is fixed on a Plexiglas disc. Reflectance spectra are measured from the rear side. (Reproduced from [267] and [269] with permission of the American Chemical Society and Elsevier Science Publishers, respectively).

A concentration detector such as the differential refractometer is shown here connected in series with the capillaries. Uie following conponents are typically used in the viscometer stainless steel capillaries of 1/16-in. o.d. and 0.016 in. i.d. X 8 in. long, 2 ml. sanple loop, Celesco pressure tramsducers of 1 psi rating, Valeo 6 port sanple valve. Burr Brown Log 100 OP. type differential log-anplifier, VWR-1145 circulation tenperature bath (-15 to 150 C). Several liquid chromatographic pumps have been used. A Du Pont 860 pump was used to obtain the data reported in this work. 

Details of the SEC/Viscometer detector system have been described previously.(16) The key component of the viscometer detector is a differential pressure transducer (CELESCO Model P-7D, Canoga Park, CA) with a jf25 psi pressure range. The transducer monitors the pressure drop across a section of stainless steel capillary tubing (length 2 ft., I.D. = 0.007 in.). Pump pressure fluctuations... 

Methyl bromide was kept in an ampoule at 0 °C and was displaced by the introduction of 1.8517 p. s of mercury from the motorburette. The methyl bromide was passed through a 2-m stainless steel capillary heating coil which was placed in the thermostat water. In order to derive the enthalpy of reaction of liquid methyl bromide, the enthalpy of vaporization (23.0 kJmoR ) was subtracted from the value obtained for gaseous methyl bromide. 

Figure 2. A. schematic of the orifices used in sampling 1, 1 /4"-l /16" male connector 2, l/8"-o.d. (o. 1/32" i.d.) stainless steel tube 3, 2.5-mm i.d. stainless steel capillary 4, stainless steel wire.

High-Performance Liquid Chromatography. A Varian 5060 delivery system was used for this work with detection by UV absorption. Either a Varian UV-50 variable wavelength detector or a Hewlett Packard 1040A scanning diode array detector was used. All HPLC columns were packed in our laboratory (10) with 5-/um particle size Spherisorb-ODS, Spherisorb-CN (Phase Separations), or 8-pm particle size Zorbax-CN (Dupont Ltd). HPLC columns (20 or 25 cm X 4.6 mm i.d.) were coupled via short lengths of stainless steel capillary tubing (5 cm X 0.25 mm i.d.). Separation conditions were as follows ... 

Figure 22-18 shows tin electrospray interface for capillary electrophoresis. The silica capillary is contained in a stainless steel capillary held at the required outlet potential for electrophoresis. The steel makes electrical contact with the liquid inside the silica by a liquid sheath flowing between the capillaries. The sheath liquid, which is typically a mixed organic/ aqueous solvent, constitutes —90% of the aerosol. 

The objective of this test was to assess the wax deposition tendency of Troll crude in a cool subsea flowline. The equipment consists of a thermostatted stirred vessel from which crude oil is circulated by a gear pump through a thermostatically controlled stainless steel capillary. Tne temperature in the vessel was maintained at 6S°C and the capillary tube was held at a constant temperature below the cloud point. 

D, entrance for eluting solvent E, Swagelok tee F, stainless-steel tubing G, Swagelok union H, stain-less-steel column I, Swagelok reducing union J, disc of Dacron sail doth K, stainless-steel capillary tubing. 

M. Konishi, Y. Mori, and T. Amano, High-performance packed glass-lined stainless steel capillary column for microcolumn liquid chromatography, Anal. Chem., 57 2235-2239 (1985). 

The stainless steel micro reactor (figure 2) is constructed for catalyst pellet sizes of 0.175 to 0.20 mm. The reactor exit is connected via 0.9 m stainless steel capillary (i.d. 0.2 mm) to the analysing unit. The reactor and part of the capillary is mounted in an electric oven. A continuous stream of carrier gas passes the four way valve, then the catalyst bed, and flows via a stainless steel capillary into the detector. The carrier gas can be switched to pulse gas with the four way valve. The pressure in the reactor is determined by the resistance of flow in the capillary. The pressure difference between the carrier gas and the pulse gas is measured with a differential pressure detector. During the experiment the gas velocities of the carrier and the pulse gas are equal. The gasses are regulated by mass flow controllers. The gases used in the experiments were of a high purity. 

The acid concentration should be as low as possible. The nebuliser fitted as standard may have a stainless steel capillary tube which will be attacked by acid over a period of time. Solutions containing more than 5% mineral acid should be nebulised using a nebuliser having a platinum/iridium capillary. A corrosion-resistant nebuliser having a plastic throat is required for solutions containing hydrofluoric acid. Additionally, in this instance, a teflon impact bead must replace the standard glass one where these are employed. 

Gas thermometer bulb a. This is a Pyrex bulb with a volume Fof about 100 cm, with an attached glass capillary passing through a large rubber stopper. The upper end of this capillary tube is connected, by a length of flexible stainless-steel capillary tubing, to the manometer. 

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