sample 



1 - extraction (toluene methanol-soxhlet) 



2 - pentane, water + sodium chlorida 



weight before saponification 

 AVSP 



saponification with KOH 



weight after saponification 

 APSP 



separation with SEP PAK 



hexane elution 



chloroform elution 



fraction hydrocarbons. 

 FA 



polar fraction 

 FB 



Each fraction was weighted by gravimetry (Balance: Perkin Elmer AD2Z, 1/10 of 

 ug) . In each case, the fraction FA was chroma tog raphed on a capillary column 

 (OV1 or SE52) with a Girdel or a Carlo Erba Fractovap 4160. The fractions FA 

 and FB were also analyzed by high-pressure liquid chromatograph (column RP 18, 

 radial pressure, Waters-type detector). Since the FA fraction may contain 

 saturated, unsaturated, or aromatic hydrocarbons, fluorescence spectrometry 

 (Perkin Elmer 3000) was used especially during the 1980 survey when 

 biodegradation rates were higher. Infrared spectroscopy (Perkin Elmer 125 and 

 225) was also used systematically to show the absence of carbonyl functions on 

 the FA fractions. .During the 1980 campaign, it appeared that some of the 

 chromatograms of the FA fractions were not sufficiently resolved due to the 

 absence of saturated hydrocarbons. However, as they represented a substantial 

 weight (A. * 257 g; A, ■ 14 g) , NMR spectroscopy (C 13 and proton 250 Mz 

 Cameca) was used to denote the presence of heavy-weight compounds with fused 



103 



