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Dual spray

In tandem MS mode, because the product ions are recorded with the same TOF mass analyzers as in full scan mode, the same high resolution and mass accuracy is obtained. Isolation of the precursor ion can be performed either at unit mass resolution or at 2-3 m/z units for multiply charged ions. Accurate mass measurements of the elemental composition of product ions greatly facilitate spectra interpretation and the main applications are peptide analysis and metabolite identification using electrospray iomzation [68]. In TOF mass analyzers accurate mass determination can be affected by various parameters such as (i) ion intensities, (ii) room temperature or (iii) detector dead time. Interestingly, the mass spectrum can be recalibrated post-acquisition using the mass of a known ion (lock mass). The lock mass can be a cluster ion in full scan mode or the residual precursor ion in the product ion mode. For LC-MS analysis a dual spray (LockSpray) source has been described, which allows the continuous introduction of a reference analyte into the mass spectrometer for improved accurate mass measurements [69]. The versatile precursor ion scan, another specific feature of the triple quadrupole, is maintained in the QqTOF instrument. However, in pre-... [Pg.35]

The MC-ICP-MS measurements were performed at a power of about 1200 W, which correspond to so-called hot plasma conditions. The stable introduction system (SIS) used consists of a quartz dual-spray chamber with a low-flow perfluoroalkoxy (PFA) microconcentric nebulizer, which produces a flow rate of approximately 50 pL/min. A conventional H cone system was used. Typically, a ° Pb signal of 4 V per 100 ng/mL is obtained with Faraday cup detectors (10 fl). The instrument is located in a clean laboratory (ISO 7, NF ISO 14644-1). The T1 spike technique, which allows in-run instrumental bias correction, was used. The required set of Faraday cups simultaneously collects the following masses Hg or Hg, Tl, Pb -h Hg, =T1, ° Pb, Pb, and Pb (Thble 31.1). A gain calibration of all the Faraday cups was carried out to determine the correction coefficients between all the Faraday cups, after the most efficient instrumental settings were determined by using a pure Pb standard solution (SRM-981) at 50 n mL. Then, the peak shape at all masses of interest was evaluated. For a given analysis, 5 blocks of 10 cycles with 8-s integration time per peak were recorded in static mode for common samples over 7 min [9]. [Pg.681]

Solutions of a salt of coating metal, and a reducing agent are. sprayed on the object from a dual spray gun. Silver mirrors are produced by using the following solutions ... [Pg.296]

Hollow Sprays. Most atomizers that impart swid to the Hquid tend to produce a cone-shaped hoUow spray. Although swid atomizers can produce varying degrees of hoUowness in the spray pattern, they aU seem to exhibit similar spray dynamic features. For example, detailed measurements made with simplex, duplex, dual-orifice, and pure airblast atomizers show similar dynamic stmctures in radial distributions of mean droplet diameter, velocity, and Hquid volume flux. Extensive studies have been made (30,31) on the spray dynamics associated with pressure swid atomizers. Based on these studies, some common features were observed. Test results obtained from a pressure swid atomizer spray could be used to iUustrate typical dynamic stmctures in hoUow sprays. The measurements were made using a phase Doppler spray analyzer. [Pg.331]

Gearing is single hehcal or spur gear lubrication usually is an automatic spray type. Single drives are used up to 150 kW. Kilns requiring more than 150 kW may be equipped with dual drives, i.e., two driving... [Pg.1204]

Figure 12.5. Photograph of microdispensing system depositing an inorganic dielectric dispersion onto a patterned, metallized polyester film. The pattern is of a transistor gate electrode array. The microdispensing head atomizes the dispersion, generating a liquid spray much like a dual orifice atomizer found on an airbrush. Figure 12.5. Photograph of microdispensing system depositing an inorganic dielectric dispersion onto a patterned, metallized polyester film. The pattern is of a transistor gate electrode array. The microdispensing head atomizes the dispersion, generating a liquid spray much like a dual orifice atomizer found on an airbrush.
Dual- Orifice 20-200 A variety of aircraft and industrial gas turbines Good atomization, Turndown ratio 50 1, Relatively constant spray angle Poor atomization in transition range, Complexity in design, Susceptibility of small passages to blockage... [Pg.23]

As mentioned in the previous section, a major drawback of the simplex atomizer is the poor atomization quality at the lowest flow rate due to too-low pressure differential if swirl ports are sized to allow the maximum flow rate at the maximum injection pressure. This problem may be resolved by using dual-orifice, duplex, or spill-return atomizers. Alternatively, the atomization processes at low injection pressures can be augmented via forced aerodynamic instabilities by using air or gas stream(s) or jet(s). This is based on the beneficial effect of flowing air in assisting the disintegration of a liquid j et or sheet, as recognized in the application of the shroud air in fan spray and pressure-swirl atomization. [Pg.37]

In 1981 the Los Alamos National Laboratory investigated for EPA the thermal destruction of wooden boxes treated with penta-chlorophenol (PCP). The incineration system consisted of a dual-chamber, controlled-air incinerator, a spray quench column, a venturi scrubber, and a packed-column acid gas absorber (11). Destruction efficiencies for PCP exceeded 99.99% for combustion chamber temperatures above 980°C, 20% excess air, and a retention time greater than 2.5 s. For these conditions, TCDD and... [Pg.184]

By achieving random dispersion of the Kaolin in the sodium silicate solution prior to formation of the silica-alumina gel, it was possible to disperse the clay crystals. They condensed somewhat perpendicular to each other and were bound together by silica-alumina gel. I therefore speculated that spray drying, during which the gel system contracts, might create a dual structure. An analogy would be a house built of cards (Kaolin), cemented together with silica-alumina gel. [Pg.320]

Annular jet. This technology was developed by the Southwest Research Institute and has not been extensively used in the food industry (10). It relies upon two concentric jets. The inner jet contains the liquid core material. The outer jet contains the liquid wall material, generally molten, that solidifies upon exiting the jet. This dual fluid stream breaks into droplets much as water does upon exiting a spray nozzle ... [Pg.5]

Granulation binder spray guns are placed above the product bed. They usually consist of several spray nozzles. Dual flow nozzles are widely used to atomize granulation binder before it reaches the solids bed. A good atomization is very important for granulation operation. The nozzles should also provide uniform spray across the bed surface. [Pg.71]


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See also in sourсe #XX -- [ Pg.35 ]




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