What method is based on fragmentation and ionization of molecules using energy?

• A. Conductance
• B. Impedance
• C. Chromatography
• D. Mass spectrometry

Answer: (D)

Mass spectrometry is a powerful analytical technique used to determine the composition of chemical substances by measuring the mass-to-charge ratio of ions. It operates based on the principles of fragmentation and ionization of molecules. In mass spectrometry, a sample is first ionized, which often involves the application of energy to break molecular bonds, causing the molecules to fragment into smaller ions. These fragments are then analyzed in a mass spectrometer, where their mass-to-charge ratios are measured, allowing for the identification and quantification of the original compounds in the sample.

The ionization process can involve several techniques, such as electron ionization or electrospray ionization, each introducing energy to the molecules in different ways. The data obtained provide insights into the structure and chemical properties of the molecules. This method is particularly useful for analyzing complex mixtures and is widely used in various fields including biochemistry, pharmaceuticals, and environmental science.