Solvent-evaporation-mediated direct

Fujita S, Nakano H, Ishii M, Nakamura H, Inagaki S (2006) Preparation of hierarchical porous silica and its optical property. Microporous Mesoporous Mater 96 205 Holland BT, Abrams L, Stein A (1999) Dual templating of macroporous silicates with zeolitic microporous frameworks. J Am Chem Soc 121 4308 Yamauchi Y, Kuroda K (2006) Fabrication of a Pt film with a well-defined hierarchical pore system via solvent-evaporation-mediated direct physical casting. Elec-trochem Commun 8 1677... 

As the droplets move through the hot source area, they continue to vaporize. The electric field at the liquid surface increases until ions present in the eluent are ejected from the droplet. Ions are sampled through a conical exit aperture in the mass analyzer. The ionization of the analytes takes place by means of direct ion evaporization of the sample ion or by solvent-mediated CI reactions an ion of the electrolyte ejected from a droplet reacts with a sample molecule in the gas phase and generates a sample ion that is mass analyzed. In addition, fragment ions can be observed due to the high temperatures associated with TSP negative ions are also produced by TSP, and negative ion detection is recommended for acidic compounds. 

The currently most frequently applied method for LC-MALDI-MS is automated post-column fractionation and on-plate collection in discrete spots of the LC colunm effluent. After the solvent is evaporated, the matrix solution can be added, and MALDI-MS analysis of the various spots can be performed. The procedure requires a liquid-handling robot, capable of disposition of effluent fractions at discrete spots on the MALDI target. A number of ways were proposed for deposition in discrete spots on the MALDI target, e.g., blotting via direct contact between droplet and target [139-140], piezoelectric flow-through microdispensing [141], pulsed electrical-mediated droplet deposition [142], and a heated droplet interface [143], Commercial LC-MALDI-MS devices were recently reviewed [144],... 

The emergence of thermospray ionization heralded a first ideal interface for a wide range of molecules [30,31]. With the introduction of this interface, LC/MS was accepted as a routine analytical technique. A major beneficiary of this interface was the pharmaceutical industry, which used this system to characterize drugs and metabolites. The construction and basic principle of thermospray ion source was discussed in Section 2.14 briefly, it consists of a heated probe, a desolvation chamber, and an ion extraction skimmer. When passed through a resistively heated capillary, the HPLC effluent, emerges as a mist of fine droplets into a heated desolvation chamber. Ionization of the solute molecules occurs by direct evaporation of the preformed ions or solvent-mediated chemical ionization. Thus, unlike the interfaces discussed above, the thermospray system acts as an ion source as well as an interface. Thermospray is ideally suited to coupling with conventional wide-bore columns. It is, however, confined primarily to reversed-phase HPLC separations, and it is less compatible with nonvolatile... 

Thicker membranes from polymers are usually cast as solution (drop, spin, and spray coating), and the membrane forms after evaporation of the solvent. Alternate routes are application of monomers, direct polymerization on the electrode surface, and mechanical attachment of the ready-to-use membranes. Usually, modifiers (mediators, catalysts, enzymes, etc.) are dissolved in the membraneforming solution. Membranes can be generated also by electropolymerization, most commonly from aniline, pyrrole, or thiophene [117-119] the resulting 2D structure can entrap active molecules (e.g., enzymes) or serve as anchors for the actual modifier. Attachment of active molecules to polymeric structures can... 

In a thermospray interface (Figure 3B), the column effluent is rapidly heated in a narrow bore capillary such that partial (ca. 90%) evaporation of the solvent is achieved inside the capillary. As a result, a mist of vapour and small droplets is formed in which the heated droplets further evaporate and ions are generated, either by the thermospray ionization process based on ion evaporation or by solvent-mediated chemical ionization initiated by electrons from a heated filament or a discharge electrode. The excess vapour is pumped away directly from the ion source. 

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