Liquid samples are most often introduced into the ICP-MS by an adjustable peristaltic pump. First, a nebuliser generates an aerosol in a spray chamber that allows only the finest aerosol droplets to pass. The sample then enters a high power argon plasma which rapidly desolvates, atomises, and ionises the sample creating a beam of singly charged positive ions.
These ions are rapidly accelerated into the vacuum of the mass spectrometer via the sampler and skimmer cones and accelerating voltages. Ion focusing is achieved by an electrostatic field followed by mass filtering in a quadrupole. The ions are sequentially detected in a single channel electron multiplier.
In cell mode, a gas (such as helium, ammonia, etc.) is introduced to a pressurised cell before the analytical quadrupole. In this collision/reaction cell, fast gas-phase kinetic energy processes and predictable chemical reactions take place. Interferences are then removed from the cell by a quadrupole while the analyte ions are allowed to pass through the reaction cell.