IN-SITU CHEMICAL IDENTIFICATION OF SIZE SEGREGATED HIGH ALTITUDE AEROSOL PARTICLES

AN IMPORTANT COMPONENT IN THE STUDY OF ATMOSPHERIC CHEMISTRY IS THE ROLE OF AEROSOL PARTICLES. THESE MAY BE CONVERTED FROM GASES, OR ACT AS RESERVOIR OR REACTION SITES FOR GASES. BECAUSE MOST CHEMICAL ANALYSES ARE PERFORMED IN THE LABORATORY FOLLOWING AIRBORNE COLLECTION, THE INTEGRITY OF THE SAMPLE CANNOT BE GUARANTEE DUE TO CHANGES IN TEMPERATURE AND TIME DELAYS PRIOR TO ANALYSIS. AN INNOVATIVE METHOD OF SIZE-SEGREGATING AEROSOLS IN THE UPPER ATMOSPHERE AND COLLECTING THEM ON A HIGHLY SENSITIVE, QUARTZ-CRYSTAL MICROBALANCE-CALLED THE SURFACE ACOUSTIC WAVE, QUARTZ-CRYSTAL, MICROBALANCE CASCADE IMPACTOR (SQCM)-WILL BE INVESTIGATED. AFTER THE COLLECTION OF THE AEROSOLS, SELECTED TARGET CHEMICALS CONTAINED ON THEM, SUCH AS HNO3, HCI, AND O3, WILL BE DETECTED BY REACTING THEM WITH A SELECTIVE REAGENT GAS. DETECTION OF GASEOUS CHEMICALS WILL BE OBTAINED SIMULTANEOUSLY, USING CHEMICALLY COATED SAW CRYSTALS FOLLOWING THE AEROSOL COLLECTOR. GAS CONCENTRATIONS IN THE SUB-TO-LOW-PPB RANGE COULD BE DETECTED SIMULTANEOUSLY WITH AEROSOLS AT A NUMBER DENSITY OF8 X 10(-3) CM(-3), ASSUMING A 0.3MUM PARTICLE OF DENSITY 1.6 G/CM(3). AN IMPORTANT COMPONENT IN THE STUDY OF ATMOSPHERIC CHEMISTRY IS THE ROLE OF AEROSOL PARTICLES. THESE MAY BE CONVERTED FROM GASES, OR ACT AS RESERVOIR OR REACTION SITES FOR GASES. BECAUSE MOST CHEMICAL ANALYSES ARE PERFORMED IN THE LABORATORY FOLLOWING AIRBORNE COLLECTION, THE INTEGRITY OF THE SAMPLE CANNOT BE GUARANTEE DUE TO CHANGES IN TEMPERATURE AND TIME DELAYS PRIOR TO ANALYSIS. AN INNOVATIVE METHOD OF SIZE-SEGREGATING AEROSOLS IN THE UPPER ATMOSPHERE AND COLLECTING THEM ON A HIGHLY SENSITIVE, QUARTZ-CRYSTAL MICROBALANCE-CALLED THE SURFACE ACOUSTIC WAVE, QUARTZ-CRYSTAL, MICROBALANCE CASCADE IMPACTOR (SQCM)-WILL BE INVESTIGATED. AFTER THE COLLECTION OF THE AEROSOLS, SELECTED TARGET CHEMICALS CONTAINED ON THEM, SUCH AS HNO3, HCI, AND O3, WILL BE DETECTED BY REACTING THEM WITH A SELECTIVE REAGENT GAS. DETECTION OF GASEOUS CHEMICALS WILL BE OBTAINED SIMULTANEOUSLY, USING CHEMICALLY COATED SAW CRYSTALS FOLLOWING THE AEROSOL COLLECTOR. GAS CONCENTRATIONS IN THE SUB-TO-LOW-PPB RANGE COULD BE DETECTED SIMULTANEOUSLY WITH AEROSOLS AT A NUMBER DENSITY OF8 X 10(-3) CM(-3), ASSUMING A 0.3MUM PARTICLE OF DENSITY 1.6 G/CM(3).