ABSTRACT
Sometimes called the mass analyzer, it is the region of the inductively coupled plasma mass spectrometry (ICP-MS) that separates the ions according to their mass-to-charge ratio. There are several very important performance specifications of a mass analyzer that govern its ability to separate an analyte peak from a spectral interference. Although ICP-MS was commercialized in 1983, the first 10 years of its development utilized a traditional quadrupole mass analyzer to separate the ions of interest. There are basically three different kinds of commercially available mass analyzers: quadrupole mass filters, double-focusing magnetic sectors, and time-of-flight mass spectrometers. Developed in the early 1980s for ICP-MS, quadrupole-based systems represent approximately 90% of all ICP mass spectrometers used today. Quadrupole rods are typically made of stainless steel or molybdenum and sometimes coated with a ceramic coating for corrosion resistance. If quadrupole has good resolution but poor abundance sensitivity, it will often prohibit measurement of an ultratrace analyte peak next to a major interfering mass.
