A quadrupole is 2 pairs of parallel, equidistant metal rods poles biased at equal, but opposite potentials. Quadrupole mass spectrometry concepts gas analysis. Data system mass detector analyzer vacuum system source inlet region more precisely mass spectrometry determines the mass of a molecule. Quadrupole mass analyzer an overview sciencedirect topics. Quadrupole and ion trap mass analysers and an introduction to. By convention, m is the numerical value for the mass of the ion and z is the numerical value for the charge of the ion. The qitms quadrupole ion trap mass spectrometer is an extraordinary instrument in that it is physically small the entire electrode assembly can be held in the palm of ones hand compared with. There are four basic types of mass analyzers found in modern ms. The quadrupole mass spectrometer is the most common mass analyzer. The mass spectrometer is essentially an instrument which. Design and operation of a portable quadrupole mass spectrometer. The quadrupole mass analyzer is one type of mass analyzer used in mass spectrometry. The quadrupole mass analyzer qms is one type of mass analyzer used in mass spectrometry.
Resolution describe the ability of a mass analyzer to separate adjacent. Media in category quadrupole mass analyzer the following 12 files are in this category, out of 12 total. The mass filter the mass filter differentiates the ions produced and selects species for detection. In the beginning of the sixties the application of massspectrometry to the. The added fields are much greater than those normally added to conventional rod. Summary of the characteristics of differ ent mass analyzers. Mathematical analysis of the quadrupole mass filter. It is also known as a transmission quadrupole mass spectrometer, quadrupole mass filter, or. Quadrupole mass spectrometers for advanced science how it works. The mass to charge ratio mz is used to describe ions observed in mass spectrometry. They are separated according to their masscharge ratio in the mass analyser e. A quadrupole ion trap is a type of ion trap that uses dynamic electric fields to trap charged particles. Quadrupole mass filter a mass analyzer that uses a stru cture of four colinear rods of.
Most quadrupole instruments are limited to unit mz resolution 3 and have a mass range of m z. It is also known as a transmission quadrupole mass. The most common form of mass filter is the quadrupole. For the mass spectrometer itselfion source, mass analyzer, detector, and data processorwe considered the commercial options available. Combined dc and rf potentials on the quadru pole rods can be set to pass only a selected masstochar ge ratio. Mass analyzers mass spectrometry chemistry libretexts. Quadrupole mass spectrometers are intrinsically lowresolvingpower instruments but are relatively cheap and robust. Mass spectrometry is an analytic method that employs ionization and mass analysis of compounds to determine the mass, formula and structure of the compound being analyzed.
Mass filter separation accomplished using combination of dc and rf electric fields. The quadrupole mass analyzer acts as a mass filter, allowing one mass channel at a time to reach the detector as the mass range is scanned. The quadrupole is a low resolution analyzer, the resolution can be improuved by gradually increasing the value of u and v as a straight line that just passes the top of the stability diagram of each ion figure 3b, such as the d1 line. The equations of motion governing the path of ions between the rods describe a complex series of. Its compact size, fast scan rate, high transmission efficiency, 2 and modest vacuum requirements are ideal for small inexpensive instruments.