This technical note provides information about the Agilent multimode source and how to optimize its performance for different applications. The multimode source can be used with both electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) techniques.
This document provides technical guidance on optimizing the Agilent Multimode Source, a versatile ionization source for liquid chromatograph/mass spectrometer (LC/MS) systems. It details how to configure the source for Electrospray Ionization (ESI), Atmospheric Pressure Chemical Ionization (APCI), or mixed modes to achieve the best performance for diverse sample types.
| Flow rate range | 400 to 1000 L/min (optimized) |
|---|---|
| Emitter power | 270 W |
Use ESI for analytes with a wide range of volatilities, especially non-polar or slightly polar ones, and for thermally fragile analytes.
Use APCI for non-volatile analytes and those that are non-polar or polar, but avoid it for thermally fragile analytes.
Methanol is strongly preferred for the organic solvent in APCI mode to prevent ion formation issues associated with acetonitrile.
Acetic acid, formic acid, and their ammonium salts generally work well for operation in positive ion mode.