The manuscript discusses EPA methods development in two areas: VOC monitoring and monitoring of dry depositon components. Whole air collection over periods of up to one day in specially prepared stainless steel canisters is beginning to be used routinely for volatile organic compounds (VOCs), although the use of solid adsorbents like Tenax is still the primary means for collection. Selective accumulation of target species in increasingly concentrated form as sampling time increases, as for collection of ambient particulate matter, or for capture of target gases on a specially prepared surface, is being used for sampling dry deposition components over periods of up to one week. The average value of the slope of the linear regression of Tenax mean versus canister mean was 0.95, while slope values for individual compounds varied from 0.80 + or - 0.06 to 1.10 + or - 0.17. Similar outdoor air study results showed a significant deterior ation in agreement. Currently three versions of dry deposition samplers are being compared and evaluated. These are the filter pack, transition flow reactor, and the annular denuder system. Results from EMSL comparison studies during the fall of 1986 show surprisingly good agreement among all three.