A FLUORESCENT SAMPLE PLATFORM FOR ULTRAVIOLET-LASER DESORPTION STUDIES

Laser desorption studies often require the visualization of an ultravi olet laser source on a metallic surface for the purpose of irradiating a specific surface site and for repositioning the laser source to oth er surface sites. In some laser desorption techniques, for example, ma trix assisted laser desorption ionization, the highest ionization effi ciency for biological samples, is obtained at or near the ablation thr eshold (10(6) W/cm(2)) of the ultraviolet-absorbing organic matrix. At these low laser intensities, the laser beam footprint is difficult to observe on the sample or the surrounding support surface. To aid this visualization, we have used anodization to incorporate a fluorescent dye into the surface oxide layer of aluminum. The result is a hard, ch emically noncontaminating, intensely fluorescent sample support surfac e for laser desorption investigations. (C) 1995 American Institute of Physics.