Figure 2-7.— Contrasting chromatograms from Ihe Ocean 250 spill. Upper, sample 205 indicates presence ol gasoline com- 

 ponents; lower, little or no gasoline components are present in sample 213. 



Table 2-5. — Concentration of gasoline range hydrocarbons in plankton samples 

 collected near the site of the Ocean 250 grounding. 





Weight of 



Weight of 



Concentration 



Concentration 





sample 



sample' 



of gasoline' 



of gasoline' 





(wet wt.) 



(dry wt.) 



hydrocarbons 



hydrocarbons 



Sample 



g 



g 



(>ih HC/g wet wt.) ( 



^g HC/g dry wt.) 



203 



3.44 



0.276 



< 88 



<1,100 



205 



1.80 



0.144 



475 



6,000 



206 



3.75 



0.301 



<128 



< 1,600 



208 



2.62 



0.201 



< 61 



< 760 



213 



11.46 



0.920 



< 20 



< 250 



214 



3.96 



0.318 



< 58 



< 720 



215 



6.08 



0.488 



<38 



< 470 



217 



7.91 



0.635 



<29 



< 360 



'Calculated from three plankton samples collected on RV Strider 78-02; 

 average moisture content was 92 ± 1%. 

 'Boiling range — C s -C,<. 



Qualitatively, the plankton sample 205 had 18 peaks in com- 

 mon with the water-accommodated gasoline chromatogram (Fig. 

 2-8). In order to examine the match of the sample hydrocarbons 

 with the hydrocarbons in the gasoline, the matching technique of 

 Hoffman and Quinn (1978) which plots individual peak areas of the 

 sample chromatogram versus the individual areas of corresponding 

 peaks of a standard was used in this study. The matching exercise in 

 this case, however, was complicated by the wide assortment of stan- 

 dards available. Trie three standards used in the course of these ex- 

 periments were as follows: 1) a 1:1:1:1:1 mixture of gasoline 



samples from each of 5 tanks; 2) water-accommodated gasoline 

 sample; and 3) 0. 1 ml of the gasoline mixture carried through the 

 saponification-extraction procedure used in the plankton analyses. 

 Hereafter, these standards will be called standard 1 , standard 2, and 

 standard 3. 



Direct comparison of the plankton sample 205 with standard 2 

 (water-accommodated gasoline) and standard 3 (processed gasoline) 

 yielded very low correlation coefficients of 0.02 and 0.12. However, 

 a comparison of standard 1 and standard 3 revealed a loss of the 

 more volatile components of the whole gas (standard 1) when car- 

 ried through the analysis procedure (standard 3). Figure 2-9 il- 

 lustrates the nature of these routine losses. When the zooplankton 

 sample 205 was corrected for these losses, the comparison of the 

 sample with standard 2 yielded an improved correlation coefficient 

 of 0.74. It is, therefore, clear that evaporative losses of hydrocar- 

 bons from the zooplankton sample, either in the environment or in 

 the analysis, was responsible in some degree for the lack of a cor- 

 relation when the sample was matched without these corrections. 



A comparison of standard 2 and standard 3 yielded a correla- 

 tion coefficient of 0.97, indicating that the losses occurring during 

 processing also occurred in the process of water accommodation by 

 evaporation or selective solubilization. If these losses occur in the 

 laboratory during the 6 h of standing needed to prepare the water- 

 accommodated standard (J. Lake' ), it is reasonable to assume that 



'"James Lake, Environmental Scientist, Environmental Protection Agency, 

 South Ferry Road, Narragansett, RI 02882, pers. commun. March 1978. 



11 



