Table 5 

 Hydrocarbons in Natural Seawater* (ppb). 



* Iliffe & Calder, 1974 



hydrocarbons (hexane eluant from silica gel) were similar to the first 

 study, while the concentration of this fraction was lower, generally 4 

 ppm or less (concentrations were calculated from gas chromatographic 

 peak areas in this case.) The dissolved aromatic hydrocarbons and 

 polyolefins (benzene eluant from silica gel) occurred at 4 ppb or less 

 and gave a complex GC spectra with most components eluting after 

 naphthalene and before pyrene. The micro-particulates on the filter 

 pad were similarly analyzed and found to contain 1 to 1 .5 times the 

 concentration of dissolved hydrocarbons. 



Phthalate Esters 



Dialkyl phthalates are abundantly produced for use as plasticizers. 



22 



