Ionization techniques are methods used to convert atoms or molecules into ions, which are charged particles. This process is essential in various fields, including chemistry and mass spectrometry, as it allows for the analysis of substances by measuring their mass-to-charge ratios. Common ionization techniques include Electron Ionization (EI) and Electrospray Ionization (ESI), each suited for different types of samples. Electron Ionization involves bombarding a gas-phase sample with electrons, leading to the ejection of electrons from the sample molecules. In contrast, Electrospray Ionization generates ions from a liquid sample by applying a high voltage, creating a fine mist of charged droplets. These techniques enable scientists to identify and quantify compounds in complex mixtures.