Aqueous fluorescence and chemiluminescence methods have been used to measure hydrogen peroxide in natural waters and in the atmosphere. Ambient hydrogen peroxide and soluble organic peroxide data is presented from the EMEX, MLOPEX and SAGA-3 experimental programs, experiments conducted in the remote marine environment. Methods to measure organic peroxide using conventional collection strategies and direct analysis by chemiluminescence or fluorescence method is approximately two orders of magnitude more sensitive than the fluorescence method. Species specific measurements of organic peroxides are also in development using high pressure liquid chromatography (HPLC) and fluorescence or chemiluminescence detection.