Ion source for ambient mass spectrometry employing a combination of laser desorption and electrospray. The sample is deposited on a metal target (top center) and irradiated with a pulsed infrared laser through an optical fiber (top right). The desorbed material passes through an electrospray of charged solvent droplets from a pneumatically assisted electrospray (center) and acquires multiple charges before passing into the mass spectrometer inlet (top center).