The alkanoic acid concentration in the range of C12ÐC32 was very high and varied from 324 to 14 300 ngm~3, CPI from 4.1 to 12.3, and C.!9 was shifted from C16 in the early September samples to C26 in the late September samples (Fig. 3c and d). Of the four classes of organic compounds isolated by flash column chromatography, alkanoic acids accounted for 50Ð60% of all the solvent-extractable organics. The ratio of the alkanoic acid concentration of the late to the early samples at the same site was 44 for Pudu and 13 for SIRIM