In refueling or headspace vapors the ratios of i-pentane/benzene, i-pentane/toluene, and
MTBE (methyl tert-butyl ether)/benzene ranged 8.7e57, 2.7e4.8, and 1.9e6.6, respectively; and they are
distinctively much higher than those previously reported in vehicle exhausts. Calculated normalized
reactivity or ozone formation potential of the gasoline vapors in China ranged 3.3e4.4 g O3g
1
VOC,
about twice that of gasoline headspace vapors reported in USA as a result of larger fractions of alkenes in
China’s gasoline vapors