Electrospray with heated capillary

Figure 12. Electrospray ion source types A) Desolvation region with gas curtain B) De.solvalion region with heated capillary...

Figure 4.9 Schematics of electrospray LC-MS interfaces with (a) a heated capillary and (b) a heated block to allow high mobile-phase flow rates. From applications literature published by (a) Thermofinnigan, Kernel Hempstead, UK, and (b) Micromass UK Ltd, Manchester, UK, and reproduced with permission.

Diagram of electrospray sources, using skimmers for ion focalization and a curtain of heated nitrogen gas for desolvation (top), or with a heated capillary for desolvation (bottom). 

Thermo Einnigan linear ion trap In the Thermo Einnigan instrument shown in Figure 3, an ion beam from an electrospray source is directed through a heated capillary, two successive rod arrays, a front lens, and into a linear ion trap composed of three sections of quadrupole hyperbolic rod arrays with Zo = 4 mm. Radial confinement of ions is effected by the trapping potential well in the center section and axial confinement by dc potentials applied to the front and rear lenses. The basic design of the linear... 

For the detection, a tandem mass spectrometer Quattro Micro API ESCI (Waters Corp., Milford, MA) with a triple quadrupole was employed. The instrument was operated in electrospray in the positive ionization mode (ESI+) with the following optimized parameters capillary voltage, 0.5 kV source block temperature, 130 °C nebulization and desolvation gas (nitrogen) heated at 400 °C and delivered at 800 L/h, and as cone gas at 50 L/h collision cell pressure, 3 x 1(F6 bar (argon). Data was recorded in the multiple reaction monitoring (MRM) mode by selection of the two most intense precursor-to-product ion transitions for each analyte, except for the ISs, for which only one transition was monitored. The most intense transition for each analyte was used for quantitative purposes. Table 2 shows MRM transitions, cone voltages and collision energies used for the analysis of the antidepressants included in the LC-MS/MS method. 

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