field-desorption mass spectroscopy

field-desorption mass spectroscopy [¦fēld dē′sȯrp·shən ¦mas spek′trä·skə·pē]

(spectroscopy)

A technique for analysis of nonvolatile molecules in which a sample is deposited on a thin tungsten wire containing sharp microneedles of carbon on the surface; a voltage is applied to the wire, thus producing high electric-field gradients at the points of the needles, and moderate heating then causes desorption from the surface or molecular ions, which are focused into a mass spectrometer.