Spark ionization (also known as spark source ionization(deprecated)) is a method used to produce gas phase ions from a solid sample. The prepared solid sample is vaporized and partially ionized by an intermittent discharge or spark. This technique is primarily used in the field of mass spectrometry. When incorporated with a mass spectrometer the complete instrument is referred to as a spark ionization mass spectrometer or as a spark source mass spectrometer (SSMS).
Typically samples are physically incorporated into two conductive electrodes (usually either carbon or silver) between which a high-voltage electric spark is produced, ionizing the material at the tips of the electrodes. If metals are being analyzed the sample may serve as an electrode.