Not your run-of-the-mill test tube

摘要

High sensitivity, capacity, and performance are hallmarks of the new generation of ion trap mass spectrometers. Over the past decade, quadrupole ion trap MS has emerged as a core technology for large-scale proteomics, structural analysis of individual proteins and peptides, forensic analysis, and pharmaceutical drug discovery. R. Graham Cooks of Purdue University describes it as a "test tube for ions." He says, "It really is just a variable electromagnetic field, the frequency and strength of which is set so as to be able to trap ions in a plane or at a point in three dimensions, depending upon the parameters that are used." Originally a curiosity, ion traps began as simple storage devices. Later, helium was introduced both to cool the ion motion and to serve as a collision partner, and ion traps became chemical reactors. Next, scan functions were developed to provide sensitive, in-depth analytical measurements, which generated information on mass-to-charge ratios and the abundance of analytes present in biomolecular samples. Altogether, these advances, along with the development of nanoflow technology and evolutionary software suites, have propelled ion traps to the position of industry workhorse in the fast-paced field of proteomics.