June 1979 
EMSL returned the second set of results and reported a 
drastically lowered result for Chester River, mouth. 
(1) Chester River, mouth 
dried by U. of Maryland 
EPA-Cincinnati 
0.3 mg/kg 
DEHP 
Univ. Maryland 
0.097+0.03 ppm 
DEHP 
(2) Chester River, mouth 
dried by EPA 
0.4 mg/kg 
DEHP 
(3) Attapulgite, spiked 
121 mg/kg 
DEHP 
200+10 ppm,DEHP 
In a telephone conversation prior to this report, EMSL commented 
that during the time of the first exchange, EPA Cincinnati had 
been experiencing some contamination problems with their homo- 
genizer used in sediment extraction. This is a probable explana¬ 
tion for the excessively high values found by EMSL in the origin¬ 
al exchange. In the report of June 1979, signed by William 
Budde, it was mentioned that EMSL procedures were the same as 
before, except that they had used a new Tissumizer (R) by Tekmar. 
While there is still some difference between the values de¬ 
termined by each laboratory in this study, we believe they are 
within acceptable limits especially considering the history of 
trace organic interlaboratory comparisons (Hilpert et al., 1978, 
Hertz et al., 1979). 
Hertz, H. S., L. R. Hilpert, W. E. May, S. A. Wise, J. M Brown, 
S. N. Chesler, and F. R. Guenther. Special Technical Publication 
686, American Society for Testing and Materials, 1979. 
Hilpert, L. R., W. E. May, S. A. Wise, S. N. Chesler, and H. S. 
Hertz. Interlaboratory comparison of determinations of trace 
level petroleum hydrocarbons in marine sediment. Anal. Chem. 
50:458-463, 1978. 
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