What is mass spectroscopy used for?

Mass spectroscopy can be used for a series of applications, ranging from the determination of chemical elements and chemical compounds in all kinds of samples to the investigation of reactions and interactions of DNA with other substances. As in mass spectroscopy you detect chemical substances based on the ratio between their masses and the charges (only ions can be detected), a wide range of information can be obtained usually with only very low amounts of the substance that you want to investigate.