Abstract: Method and apparatus for mass spectral analysis of unknown species of matter present on a surface even in extremely low concentrations. A probe beam such as an ion beam, electron beam or laser is directed to the surface under examination to remove a sample of material. An untuned, high-intensity laser is directed to a spatial region proximate to the surface. The laser has sufficient intensity to induce a high degree of nonresonant, and hence non-selective, photoionization of the sample of material within the laser beam. The non-selectively ionized sample is then subjected to mass spectral analysis to determine the nature of the unknown species.