Surface profiling of lithium with a laser-desorption mass-spectrometer microprobe

A laser-desorption mass-spectrometer microprobe has been developed to profile Li distributions on the crevice surfaces of Cr-plated rolled-joint hubs. A single laser pulse is used to desorb and ionize the surface species followed by detection of [Li.sup.+] in a time-of-flight mass spectrometer. Images of the surface Li distribution are obtained with a resolution of