Chapter 11, Problem 11.1QAP

Interpretation Introduction

Interpretation: The types of mass spectrometers that are used in ICPMS needs to be determined. The difference between them needs to be explained.

Concept introduction:Mass spectrometer is an instrument which differentiates particles according to the mass and charge. It has electromagnetic field in which heavy molecule having strong positive charge moves slow and so detector will detect it late. And according to this a graph will be generated.

Answer to Problem 11.1QAP

Based on the techniques used in respective mass spectroscopy following are the different types of spectrometers:

1. Quadrupole mass filter
2. Time-of-flight
3. Sector instruments
4. Ion traps:

1. Three-dimensional quadrupole
2. Cylindrical
3. Linear and Orbitrap

Explanation of Solution

Quadrupole analyzers utilize the wavering electric field to specifically balance out or destabilize the ways of particles going in a radio frequency(RF). quadrupole field which is framed between four parallel poles. Particles in a specific scope of mass/charge proportion are gone through the framework whenever, yet varieties to the possibilities on the bars permits a wide scope of m/z esteems to be cleared rapidly, either consistently or in a progression of characterized turns.

In the time-of-flight (TOF) method, electric field is adopted to accelerate ions via same potential. The time taken by ions to reach the detector is then observed.

If all the ions are having the same charge, then the kinetic energy tend to be similar, and the ions' velocity will depend only on the mass of the ions and it can be seen that the ions which are having a lower mass will be reaching the detector earlier than those having higher mass.

A segment field strategy or (A sector field) pursues a system that incorporates a static electric and additionally magnet attractive field to impact the speed or velocity of the particles. It twists the directions of the particles. As indicated by their mass-to-charge proportions, it very well may be found that there is more redirection of the more charged and quicker moving. This technique is utilized to choose a scope of m/z or to screen through a scope of m/z to arrange the particles present in a given issue.

Ion traps:

Three-dimensional quadrupole ion trap- This method is based on the principle that is used in the quadrupole method but there is a difference. The ions are trapped and ejected one by one. They are trapped in a quadrupole RF field. Which is defined by a space by a ring electrode and between two end cap electrodes. The sample may be internally or externally ionized inside it, in this case the ions are often introduced by an aperture in an end cap electrode.

Cylindrical particle trap-This technique is a kind of quadrupole method.Here, the terminals i.e the electrodes are framed from level rings, not from hyperbolic formed electrodes. The system permits itself for scaling down as the size of the trap is diminished; the state of the electric field which is at the focal point of the trap frames a shape like a hyperbolic trap.

Straight quadrupole particle trap - This strategy additionally shares similitude to a quadrupole particle trap, yet the difference is that it can trap particles in a two-dimensional quadrupole field, it doesn't utilize three-dimensional quadrupole field as utilized in a 3D quadrupole.

Orbitrap instruments methods have trapping technique for ions in anelectrostatically circular path around a central, spindle shaped electrode.

Conclusion

Hence, this can be concluded that types mass spectrometers are based on the techniques used in respective mass spectroscopy.