INITIAL RESULTS FROM THE NONMETHANE HYDROCARBON INTERCOMPARISON EXPERIMENT

The Non-Methane Hydrocarbon Intercomparison Experiment (NOMHICE) is de scribed. This experiment has been designed to evaluate analytical tech niques currently being used by scientists throughout the world to meas ure ambient atmospheric hydrocarbon concentrations. NOMHICE consists o f a series of planned experiments designed to identify existing proble ms in participating scientist's laboratories and to correct them. The various experimental steps (or phases) have been scheduled in order of increasing complexity so that problems can be addressed as they arise . Results are presented for the initial phases of this program. Phase 1 involved the circulation of a 2 component gravimetrically prepared s tandard to 40 laboratories throughout the world. Participants were ask ed to quantify but not identify the components. Phase 2 involved the c irculation of a more complex 16 component gravimetrically prepared mix ture to 32 participants. Participants were asked to identify and quant ify the components. Further tasks are described which will be carried out in the future.