Direct liquid injection

For areas where cooling water is either scarce or not available, direct liquid injection may be a possibility. The liquid coolant should be injected near the discharge end of the compressor to minimize lubricant dilution. Alternatively, the liquid can be flashed in a separate exchanger and used to cool the lubricant. While the cooling may appear to decrease the power to the compressor, the net effect is an increase in the power due to the additional weight flow of the extra refrigerant needed to perform the cooling. 

In reduced-flow LC-MS systems, the solvent flow into the spectrometer is reduced to a level where the pumping system can cope. Essentially, three such systems have been developed direct-liquid-introduction (DLI), flowing FAB [531] and electrospray [532]. An alternative approach to belt transport interfacing is to deliver the column eluate directly into the MS source and use Cl techniques. Methods based on this principle are called direct-liquid-injection systems, which are comprised of capillary flow restrictors, diaphragms,... 

Direct liquid injection (DLI) has been used even less. Hirter et al. [579] have reported the early analysis of a synthetic antioxidant mixture (Irganox 1010/1076/1098) by means of iRPLC-DLI-QMS with Cl. In early studies, the HPLC effluent was vaporised by laser radiation [593] both El and solvent-mediated Cl spectra were obtained in the on-line mode from analytically difficult molecules. However, the instrumentation was complex the sensitivity was not as good as that obtained by GC-MS and thermal decomposition was observed with other compounds. This direct introduction approach with enrichment was used for the analysis of phthalates. 

The Model II plants were of a greatly improved design, incorporating two basic major developments—the downflow or bottom withdrawal Fluid bed and the direct liquid injection of oil feed into the reaction zone. The downflow development permitted withdrawal of catalyst for circulation from the bottom of the bed. 

Direct liquid injection CVD [184, High film growth rates possible... 

Kang and Rhee grew bismuth oxide films at 225-425 °C by direct liquid injection MOCVD, using Bi(thd)3 dissolved in n-BuOAc. Temperatures above 325 °C tend to decrease the growth rate due to gas-phase dissociation processes. Annealing at temperatures up to 650 °C is necessary to obtain monoclinic o -Bi203. Temperatures above 750 °C convert a-Bi203 into cubic bismuth silicate due to the reaction with the silicon substrate. 

The groups of Rhee and Jun synthesized La(thd)3(tetea) (24) and La(thd)3-(tetraglyme) (25), which show an increased solubihty compared to La(thd)3, for use as precursors in direct liquid injection MOCVD. Deposition on Si(lOO) between 325 and 450 °C using argon as carrier gas along with oxygen as reactive gas lead to smooth dense... 

Other commercially available systems which come equipped with the direct liquid injection (DLI) or the continuous flow-fast atom bombardment (CF-FAB) interfaces are used less frequently (21). Because of their limited use, little information has been published about their application. 

B.M. Kolakowski, J.S. Grosser , L. Ramaley, Studies on the positive-ion mass spectra from APCI of gases and solvents used in LC and direct liquid injection, J. Am. Soc. Mass Spectrom., 15 (2004) 311. 

Kimberley E. L., Rice G. W. and Fassel V. A. (1984) Direct liquid injection sample introduction for flow injection analysis and liquid chromatography with inductively coupled argon plasma spectrometric detection, Anal Chem 56 289-292. 

Figure 1-2. (a) Schematic of MKS Direct Liquid Injection (DLI) system, (b) Detailed view of vaporizer used in DLI. system, presented courtesy of MKS. 

Other approaches include the use of a moving belt interface, compatible with conventional packed columns [19], and a split direct liquid injection interface [20]. 

The in-tube SPME method is suitable for the extraction of less volatile or thermally labile HCAs compounds [89]. The food sample is treated with HCl followed by centrifugation, the sample supernatant is neutralized with NaOH, and the HCAs are extracted by the Blue Rayon adsorption method. This method can selectively adsorb compounds having polycyclic planar molecular structures, such as HCAs, in order to concentrate them from the aqueous solution. The extract is passed through a syringe micro filter, and a capillary colunm is used as a SPME device. This column is placed between the injection loop and the injection needle of the auto sampler. The method is simple, rapid, automatic, and gives 3-20 times higher sensitivity in comparison with the direct liquid injection method [89]. 

Chemical vapor deposition refers to the formation of a nonvolatile solid material from the reaction of chemical reactants, called precursors, being in vapor phase in the right constituents. A reaction chamber is used for this process, into which the reactant gases are introduced to decompose and react with the substrate to form thin film or powders There are several main classification schemes for chemical vapor deposition processes. These include classification by the pressure (atmospheric, low-pressure, or ultrahigh vacuum), characteristics of the vapor (aerosol or direct liquid injection), or plasma processing type (microwave plasma-assisted deposition, plasma-enhanced deposition, remote plasma-enhanced deposition)... 

Figure 4.62. CVD/ALD delivery methods for liquid precursors. Shown are (a) carrier gas bubbling of a volatile precursor, (b) vaporization of a volatile precursor, and c) direct liquid injection (DLl) of a volatile/ non-volatile precursor.

FIGURE 14-4 Scanning electron microscopy images of Pt nanoparticles deposited by direct liquid injection MOCVD on the microporous side of a commercial GDL. Reproduced from Reference [64] with permission of... 

Programmed-temperature vaporizer, an inlet system designed to perform a temperature programmed injection, a cold injection system for direct liquid injection for split or splitless injection, solvent spHt technique and cryo-enrichment. 

Lee D-J, Kang S-W, Rhee S-W (2002) Chtanical vapor deposition of ruthenium oxide thin films from Ru(tmhd)3 using direct liquid injection. Thin Solid Films 413(l-2) 237-242, http // dx.doi.org/10.1016/S0040-6090(02)00439-X... 

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