in Figure 10 is likely to be due to the fulvic acid component 
which occurs in natural water and sediment extracts. Although a 
number of Morgan Creek and Chester River water samples were run 
by the same technique, the method was frustrated by early plug¬ 
ging of the Sep Paks. This prevented the obtaining of large 
enough samples to give the needed sensitivity. 
Analysis was made by LC of Tenneco Pond sediment. The re¬ 
sult is shown in Figure 11. The concentrations are so high that 
peak verification by GC/MS was readily demonstrated and quanti¬ 
tative interpretations are thus possible. The retention volumes 
are consistent with the presence of humic acid, of DEHP 
(1.8 + 0.1) x 10 3 ppm and a second determination of (1.3 x + 0.2) 
x 10 3 ppm, of DIDP (1.4 +0.2) x 10 3 ppm and of DTDP 
(1.9 + 0.2) x 10 3 ppm. The qualitative identifications by LC 
were each confirmed by GC/MS-SIM retention times of m/z 149. 
A few miles downstream from Tenneco on Morgan Creek sediment 
samples were taken for LC analysis. Comparison was made to 
humic acid under the same conditions. These results are shown 
in Figures 12 and 13, respectively. It is clear that the natural 
background, the multiple peaks due to fulvic and humic acid con¬ 
stituents, seriously interfere with and prevent quantitative use 
of these LC results. Sediment samples taken from the 
Chestertown Bridge and from the Chester River (site 5, Figure 4) 
showed no evidence for DEHP, apparently less than 1.0 ppm. 
Artifact peaks were observed and these suggested exaggerated 
levels of DIDP and DTDP. The GC/MS technique gave qualitative 
but not quantitative confirmations of DEHP and DBP so these were 
concluded as present at both sites. The DBP peak position was 
found to be consistently obscured in the LC by the humic com¬ 
ponents. Significantly, this was the only alkyl phthalate which 
Tenneco did not make, but which is otherwise massively produced 
by U.S. industry. Second, certain peaks evident at the equivalent 
of <10 ppm levels by LC were found by GC/MS not to be phthalates. 
Attention was then directed to the GC/MS technique which was con¬ 
sidered necessary for identification and measurement of DBP and 
DEHP at levels below 100 ppm. The LC technique offered prelimi¬ 
nary qualitative utility and it was the more reliable for meas¬ 
uring DIDP and DTDP. 
Preliminary Qualitative Results Using GC and GC/MS 
A preliminary grab sample of Tenneco Pond sediment was 
obtained. The sediment was desiccated and then extracted by 
methanol using ultrasonic agitation. Centrifugation gave a 
clear filtrate which was then analyzed by gas chromatography. 
The result showed a single peak which accounted for >95 percent 
of all volatiles apparent by the FID detector. 
Gas chromatographic retention times and mass fragmentation 
patterns showed clearly that the very conspicuous main organic 
volatile component in Tenneco Pond sediment is the same as the 
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