It has been well established during the past decade that atoms and molecules can be efficiently ionized by illuminating them with intense pulses of laser radiation and that spectroscopic information about neutral molecules¹ and ions² can be extracted. One of the major achievements of analytical science, the detection of single atoms, has been achieved by exploiting laser ionization.³ Equivalent sensitivity toward molecules is certainly attainable in principle. However practical systems for detecting molecules must overcome problems associated with background ionization and excited-state molecule dynamics. To increase the detection selectivity made possible by the laser ionization process, sample molecules are introduced into our system through a gas or supercritical fluid chromatograph; the ions generated are mass resolved by a time-of-flight mass spectrometer.⁴ Recent improvements in our chromatographic systems, mass spectrometer resolution, and GC-MS interface are discussed, along with the application of these to the detection of minute quantities of various priority pollutants.