PHOTOCHEMICAL AMPLIFIER FOR GAS ACHROMATOGRAPHY BASED DETECTION OF SINGLET OXYGEN

THE DEVELOPMENT OF A NEW DETECTOR FOR GAS CHROMATOGRAPHY BASED ON PHOTOCHEMICAL AMPLIFICATION IS PROPOSED. IN THE PROPOSED SYSTEM, THE EFFLUENT OF THE GAS CHROMATOGRAPHY MIXED WITH A GAS STREAM CONTAINING OXYGEN AND ENTERS A PHOTOCHEMICAL REACTOR. ANALYTES WHICH ABSORB UV RADIATION ARE QUENCHED BY MOLICULAR OXYGEN TO FORM SINGLET OXYGEN WHICH ISSUBSEQUENTLY DETECTED SELECTIVELY BY PHOTOIONIZATION. BE- CAUSE THE ANALYTE ONCE QUENCHED BY OXYGEN CAN ABSORB ANOTHE-ER PHOTON, THE REACTION IS PHOTOCATALYTIC AND SHOULD RESULT IN THE FORMATION OF 5 OF 50 MOLECULES OF SINGLET OXYGEN PER MOLECULE OF ANALYTE. THIS PHOTOAMPLIFICATION SHOULD PERMIT SUB-PICOGRAM TO LOW FEMTO GRAM DETECTION LIMITS FOR ENVIRON-MENTALLY IMPORTANT COMPOUNDS SUCH AS POLYCYCLIC AROMATIC HY-DROCARBONS AND THEIR NITRO-DERIVATIVES. SUCCESSFUL COMPLETION OF THE RESEARCH TO BE CONDUCTED DUR-ING PHASE I AND PHASE II PROJECTS WILL RESULT IN AN IMPROVE-MENT OF THE SENSITIVITY AND EXTEND THE UTILITY OF THE EXIST-ING DETECTORS FOR GAS CHROMATOGRAPHY. NEW ANALYSIS OF HAZ- ARDOUS COMPOUNDS IN EVNIRONMENTAL SMAPLES BY REDUCING OR ELIMINATING LENGTHY SAMPLE PRE-CONCENTRATION, THUS ALLOWING "REAL TIME" MONITORING AND LOWER ANALYSIS COSTS.