Photochemical formation of peroxides in the ethane/H2O/O2/N2 system was studied with LP-FTIR and HPLC techniques. Hydrogen peroxide, ethyl hydroperoxide (CH3CH2OOH, EHP) and peroxyacetic acid [CH3(O)OOH, PAA] were proved to be the peroxide products in the degradation of ethane. Moreover, methyl hydroperoxide (CH3OOH, MHP) hydroxymethyl hydroperoxide (HOCH2OOH, HMHP) and dimethyl peroxide (CH3OOCH3, DMP) were identified for the first time in the system. The dominant peroxide products were H2O2, EHP and MHP with the maximum calculated yields of 6.8%, 6.4% and 6.7%, respectively. MHP was mainly generated from the photolysis of acet aldehyde formed in thee degradation of ethane. The identification of HMHP provide san evidence for the formation of Criegee intermediate.CH2OO. in the degradation of ethane. The OH radical initiated degradation of ethane was possibly one of the main sources of H2O2, MHP and EHP in the troposphere.

Key words: ETHANE, HIGH SPEED LIQUID CHROMATOGRAPHY, PHOTOCHEMICAL SMOG, INFRARED SPECTROPHOTOMETRY, HYDROXY GROUP, FREE RADICAL REACTION, DEGRADATION REACTION, PHOTOCHEMICAL REACTION, PEROXIDE