This document discusses mass spectrometry, including its principles, instrumentation, and applications. Mass spectrometry works by ionizing molecules and measuring their mass-to-charge ratios, producing a mass spectrum. This technique is used to determine molecular masses and structures of unknown compounds. It has various applications in analytical chemistry and biology due to its ability to distinguish between substances with high sensitivity and specificity.

1. PRESENTED BY:- SWADHIN ROUTRAY
REGD. NO. :-2161611005
M.PHARM 1ST YEAR
GUIDED BY :- Dr. ANINDYA BOSE

2. 1. INTRODUCTION
2. PRINCIPLE
3. THEORY
4. INSTRUMENTATION
5. APPLICATION
6. REFERENCES

3. • Mass spectrometry (MS) is an analytical technique that is
used to measure the mass-to-charge ratio of ions.
• The results are presented as a mass spectrum, a plot of
intensity as a function of the mass-to-charge ratio. Mass
spectrometry is used in many different fields and is applied to
pure samples as well as complex mixtures.
• A mass spectrum is a histogram plot of intensity vs. mass to
charge (m/z) in a chemical sample, usually acquired using an
instrument called a mass spectrometer. (1)

4. • In mass spectrometry, fragmentation is the dissociation of energetically
unstable molecular ions formed from passing the molecules in the ionization
chamber of a mass spectrometer. The fragments of a molecule cause a
unique pattern in the mass spectrum.
• The most intensive peak in a spectrum is called the "Base Peak", whose
intensity is taken as 100 percent. This ion exists most abundantly in the ion
source and represents the most stable ion, which is useful for identifying the
compound.
• In the mass spectrum, the heaviest ion (the one with the greatest m/z value)
is likely to be the molecular ion. (2)

5. • Mass spectroscopy is the most accurate method for
determining the molecular mass of the compound and its
elemental composition.
• In this technique, molecules are bombarded with a beam of
energetic electrons.
• The molecules are ionized and broken up into many
fragments, some of which are positive ions.
• Mass spectra is used in two general ways:
To prove the identity of two compounds.
To establish the structure of a new compound.

6. • The mass spectrum of a compound helps to establish the
structure of a new compound in several different ways:
It can give the exact molecular mass.
It can give a molecular formula or it can be reveal the presence of certain
structural units in a molecule. (3)

7. • A parent ion results when one electron is removed from the parent
molecule of the substance
• M+e --------------> M+ + 2e
• The m/e value of the parent ion is equal to the molecular mass of
the compound. In a few cases, the parent ion peak may be the base
peak and can be easily recognized. In most of the cases, parent ion
peak is not the base peak and is often of very small abundance. Many
elements occur naturally as isotopes; out of these the lightest one
greatly predominates. The mass spectrometer is designed to perform
three basic functions. (4)

8. These are:
1. To vaporize compounds of varying volatility
2. To produce ions from the neutral compounds in the vapour phase.
3. To separate ions according to their m/e ratio and to record them.

10. The four main parts of mass spectrometry are discussed below:
• Ionizer – The bombarding of the sample is done by the
electrons. These electrons move between cathode and
anode. When the sample passes through the electron stream
between the cathode and anode, electrons with high energy
knock electrons out of the sample and form ions.
• Accelerator – The ions placed between a set of charged
parallel plates get attracted to one plate and repel from the
other plate. The acceleration speed can be controlled by
adjusting the charge on the plates.

11. •Deflector – Magnetic field deflects ions based on its charge
and mass. If an ion is heavy or has two or more positive
charges, then it is least deflected. If an ion is light or has
one positive charge, then it is deflected the most.
•Detector – The ions with correct charge and mass move to
the detector. the ratio of mass to charge is analyzed through
the ion that hits the detector. (5)

12. • Mass spectrometry is a efficient method to elucidate the
chemical composition of a sample or molecule. More recently,
it has been used to classify biological products, in particular
proteins and protein complexes, in a number of
species. Usually, mass spectrometers can be used to classify
unknown substances by molecular weight measurement, to
measure known compounds, and to determine the structure
and chemical properties of molecules.
• Due to its capability to distinguish between substances, Mass
spectrometry is used to determine unknown substances.
• To identify the isotopes of a substance.
• In analytical laboratories that study the chemical, physical
and biological properties of substances. It is favored over
several other analytical techniques as it has less background
interference since it is performed in a vacuum. (6)

13. 1. Downard KM (2007). "Historical account: Francis William Aston: the man
behind the mass spectrograph". European Journal of Mass
Spectrometry. 13 (3): 177–90
2. Cooks, R. G. and A. L. Rockwood (1991). "The 'Thomson'. A suggested unit
for mass spectroscopists." Rapid Communications in Mass Spectrometry
5(2): 93.
3. Eiceman, G.A. (2000). Gas Chromatography. In R.A. Meyers
(Ed.), Encyclopedia of Analytical Chemistry: Applications, Theory, and
Instrumentation, pp. 10627. Chichester: Wiley.
4. https://www.pharmatutor.org/pharma-analysis/discuss-the-theory-of-
mass-spectroscopy
5. Syed SU, Maher S, Taylor S (December 2013). "Quadruple mass filter
operation under the influence of magnetic field". Journal of Mass
Spectrometry.
6. https://byjus.com/Application-of-mass-spectrometry