TABLE 10. METHODOLOGY 
Step 
Procedure 
Reagents Added 
Conditions 
1 
Isopiestic dehydration 
Na^O^dried 
Closed system 
of sediment 
at 180 °C 
22°C, 1 atm 
2 
Ultrasonic extraction 
CH 2 CI 2 contain- 
Closed system 
with CH~C1 0 
ing 0.4 or 4.0 
t = 30 °C 
ppm DMEP internal 
standard 
3 
Centrifugation 
None 
Closed system 
t = 10°C 
2500 x G 
4 Evaporate solvent XAD-2 filtered Open system 
N 2 : 
(a) Isooctane 
added for 
GC or GCMS 
(b) THF added, 
CH 2 C1 2 re¬ 
moved, for 
HPLC 
Preliminary Liquid Chromatographic Analysis 
High performance liquid chromatography has been reported 
for analysis of alkyl phthalate esters (Heilman 1978) . This 
technique was adapted to confirm GC measurements on Tenneco 
Pond sediment, as a screen and to provide upper limit data on 
samples containing small amounts of alkyl phthalates. The 
Heilman method is based on adsorption chromatography. A more 
reliable method was developed based on partition chromatography 
using water-tetrahydrofuran as the carrier with bonded C18 as 
the stationary phase. 
A surface sample of water from the environment was trans¬ 
ferred onsite to the barrel of a baked glass Luer-type syringe. 
A Sep Pak C18 cartridge was already fixed in place. The water 
was then passed through the cartridge using hand pressure after 
inserting the plunger into the barrel of the syringe. This was 
continued until the back pressure became too great. Then the 
cartridge was returned to its original protective envelope, 
sealed, and labeled. 
Preliminary laboratory tests had shown that THF (tetrahydro- 
furan) gave sharper peaks than either methanol or isopropanol 
which are widely used. The recovery of DEHP standard was about 
53 
