Electron Ionization (EI) is a technique used in mass spectrometry to analyze chemical compounds. In this process, a sample is vaporized and then bombarded with high-energy electrons. This interaction causes the molecules in the sample to lose electrons, resulting in the formation of positively charged ions. These ions are then accelerated and analyzed based on their mass-to-charge ratio. Electron Ionization is particularly effective for small, volatile molecules and is commonly used in laboratories for identifying and quantifying substances in various fields, including chemistry and biochemistry.