Chapter 14, Problem 76CP

Interpretation Introduction

Interpretation: The formulas for the ions responsible for the given peaks have to be determined.

Concept Introduction:

Mass spectrometry:

• It is a technique used to find out the molecular weight of the compounds and thus providing the structure and chemical properties of different molecules.
• The sample ion is converted into gaseous ions with or without fragmentation and are characterized by their charge to mass ratios and relative abundances.
• Mass spectrum is a plot of the relative abundance of the generated ions as a function of the charge to mass ratio.

Electron impact ionization:

It is an important technique in mass spectrometry. The sample is first vaporized and converted into ions. This technique involves the bombardment of compound with high energy electrons which carry a high amount of energy. When this much energy strikes the sample molecule, it causes one of the electrons to be ejected. Thus this technique generates both a radical and a cation and is called the molecular ion.

Molecular ion is unstable and subject to fragmentation. The mass-charge ratio separates the molecular ion and the cationic fragments.