Hydrogen carrier gas

The phosphides tricadrnium diphosphide [12014-28-7], Cd2P2, cadmium diphosphide [12133-44-7], CdP2, and cadmium tetraphosphide [12050-26-9], CdP, may all be prepared by indirect fusion of the elements, usually by passing phosphoms vapors, in a nitrogen or hydrogen carrier gas. 

The reduction of the sample was made at 2250 K In a flowing stream of hydrogen carrier gas ( SO cm /mln). The total pressure of the carrier gas was approximately 1 atm. The water vapor produced during the reduction was swept by the carrier gas Into an electrolytic-type (P2O5) moisture monitor and a continuous recorder trace of the water concentration as a function of time was obtained. A typical plot of the moisture content of the carrier gas as a function of time Is shown In Figure 3. The region on the left side of this figure where the moisture content... 

Figure 3. Moisture concentration (ppm H2O) in the hydrogen carrier gas as a function of time during the preparation of the plutonium sesquioxide sample by hydrogen reduction at 2250 K.

Figure 2.7 Activity test of an uncoated fused silica capillary after deactivation with poly(phenyliaethylhydrosiloxane), (A), and before deactivation, (B). Precolunn 15 x 0.20 m I.D. coated with SE-54. Test columns 10 a x 0.20 I.D. The column tandem was programmed from 40 to I80 c at a C/min after a 1 min isothermal hold with a hydrogen carrier gas velocity of 50 cm/s. The test mixture contained 10 n-decane, Cg-NH = l-aminooctane, PY 3,5-dimethylpyrimidine, C 2 n-dodecane, - 1-amlnodecane, DMA ...

In a typical experimental arrangement, the injection block heater of the gas chromatograph is used to heat a short catalyst bed containing platinum, palladium, copper or nickel coated on a diatomaceous support. The catalyst bed can be the top portion of a packed column or a precolumn connected to a packed or open tubular column. Hydrogen carrier gas flows through the heated catalyst bed (220-350 0) and then into the column. The sam B is injected by... 

Supersonic molecular beam (SMB) mass spectrometry (SMB-MS) measures the mass spectrum of vibra-tionally cold molecules (cold El). Supersonic molecular beams [43] are formed by the co-expansion of an atmospheric pressure helium or hydrogen carrier gas, seeded with heavier sample organic molecules, through a simple pinhole (ca. 100 p,m i.d.) into a 10 5-mbar vacuum with flow-rates of 200 ml. rn in. In SMB, molecular ionisation is obtained either through improved electron impact ionisation, or through hyperthermal surface ionisation... 

The actual selectivity depends on the nature of the catalyst. For example, the following data were reported for n-hexane transformed over platinum and palladium supported on the same alumina 44) (pulse system, hydrogen carrier gas, T = 520°C) ... 

Diastereomer ratios were determined by gas chromatography. Since the aldol adduct undergoes retroaldol reaction on the column, it must be silylated prior to injection. Approximately 5 mg of the crude adduct is filtered through a short plug of silica gel to remove any trace metals. The material is taken up into 1-2 mL of dichloromethane in a 2-raL flask or small test tube. To this solution are added 4-5 drops of N,N-diethyl-1,1,1-trimethylsilylamine and a small crystal of 4-(N,N-dimethylamino)pyridine (Note 11), The solution is stirred for 2 hr and injected directly onto the column. (Column conditions 30 m x 0.32 mm fused silica column coated with OB 5, 14 psi hydrogen carrier gas, oven temperature 235°C). 

The enantiomeric excess was determined to be >99% by capillary GLC analysis (30 ra x 32 tim WCOT column coated with Carbowax 20 M, hydrogen carrier gas, linear velocity ca. 94 cra/s, oven temperature 225°C) of the imide derived from the Mosher acid chloride. ... 

CVD of SiC normally uses silane and a hydrocarbon as the precursor gases and a hydrogen carrier gas. The gases pass over a heated graphite susceptor that is coated by SiC or tantalum carbide (TaC). 

Mercury telluride (HgTe) was first made by vapour phase epitaxy in 1984. This preparation illustrates the use of ultraviolet radiation as the energy source for decomposition. Diethyltellurium ((C2H5)2Te) vapour in a stream of hydrogen carrier gas... 

The hydrogen carrier gas velocity was 50 cm/s. The carrier gas velocity was measured by the methane peak retention time as recommended by Rijks (15). 

Hydrocarbons fed to reactor as 3-mg. shots (pulse-tvpe operation) in a stream of hydrogen carrier gas. 6 Conditions 350°C., total pressure = 1 atm., catalyst charge = 1 g., carrier gas rate = 3 liters/hr. 

FIGURE 6.2 Height equivalent to a theoretical plate (H) of a GC-separated compound versus average carrier gas velocity for a 3-m-long silicon channel coated with non-polar dimethyl polysiloxane stationary phase (a) native silicon surface (b) oxidized silicon surface. Plots A are for hydrogen carrier gas, and plots B are for air carrier gas [598]. Reprinted with permission from the American Chemical Society. 

Set the oven temperature to ramp 140° to 350° at a rate of 10°/min (total run time of 21.0 min). Set the track mode to on (injector temperature follows the oven temperature conditions). Set the injection mode to on-column injection. Set the FID at 375°. Set the hydrogen carrier gas constant flow mode to on with a pressure of 5.5 psi (140°). 

Reduction reactions of halide precursors are very commonly used in CVD technologies. In many cases, the use of a hydrogen carrier gas provides the reducing agent in excess, as in the cases of tungsten deposition from the hexafluoride WF + 3 W(s) + 6 HF, or the... 

Fig.4. Direct aqueous injection, 1/itof test mixture (Table D.Oparating conditions temperature 30° 3 min, 8°/min to 120, hydrogen carrier gas 50 cm/sec (100 °C), chart speed 1 cm/min...

Fig. 8. Water pollutants (Table 1) by Megabore columns. Operating conditions hydrogen carrier gas 8.0 mVmin temperature — 30 °C for 3 min, 5°/min to 120 °C chart speed 0.5 cm/min.

Fig. 1 Fast GC analysis of aviation turbine engine fuel using a typical laboratory GC instrument. Conditions hydrogen carrier gas temperature programming rate, 70-170°C at 120°C/min (actual 75°C/min) microbore column 3 m x 0.10 mm ID.

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