Device and method using microplasma array for ionizing samples for mass spectrometry

A device includes a first substrate having a principal surface having a plurality of sample sites having a corresponding sample; a second substrate having a principal surface facing and spaced apart from the principal surface of the first substrate, the second substrate having a plurality of ultraviolet emission sites corresponding to the sample sites of the first substrate, each of the ultraviolet emission sites being spaced apart from and facing a corresponding one of the sample sites of the first substrate, each of the ultraviolet emission sites being configured to emit ultraviolet light to a corresponding one of the sample sites on the first substrate, and to ionize at least a portion of a sample provided at each sample site; and an ion extraction device configured to extract ions from a gap between the first substrate and the structure.