Recovery Tests— 
Several experiments were carried out to show whether DEHP 
could be added to the measurement system and then recovered 
without serious loss. The results are summarized in Table 13 f 
which is largely self-explanatory. The most serious loss seemed 
to occur when dichloromethane containing a DEHP spike was de¬ 
liberately evaported to remove all of the solvent. When this 
was done a 7 percent DEHP loss was observed. To prevent this 
in the actual procedure, a small amount of isooctane, a higher 
boiling solvent, was added to prevent the volatilization and 
no other measurements in the report involved total solvent 
volatilization exhibited here for test purposes. 
TABLE 13. DEHP RECOVERY MEASUREMENTS USING DICHLOROMETHANE 
Sample 
Procedure 
Trials 
Percent 
Recovery 
Spiked Solvent* Remove 95% of solvent. ^ 
Add fresh solvent to 
bring to initial volume. 
Spiked Solvent* Remove 100% of solvent. 3 
Add fresh solvent to 
bring to initial volume. 
100 + 2 
93 + 1 
Spiked Blanki 
(attapulgite) 
Remove 98% of water by 4 
desiccation. 
Spiked Blank 
(attapulgite) 
Ultrasonic extration by 
dichloromethane 
98 + 1 
5 ml of CH 2 C1 2 containing 1 mg of added DEHP. 
1 g of Attapulgite containing 0.2 mg of added DEHP. 
N.B.(1) Internal standard = d-10-anthracene 
N.B. Reagent blanks are as follows: 
CH 2 C1 2 = 20+10 ppb of DEHP 
Attapulgite = 10 ppb of DEHP 
Effect of Varied Methodology and Combinations— 
The establishment of a 2.0 minute sonication procedure for 
extracting dry sediment with dichloromethane was subjected to 
a series of tests to measure the completeness of the extractive 
process. The same working standard "R" was used. The sonica 
tion procedure is the same as that previously described. The 
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