Bottle cap liners (Teflon) 
1. These liners were cut from Teflon sheet using 
cork bores. They were then extracted for 
24 hours using Soxhlet extraction. 
2. Liners were stored in an air-tight, cleaned 
glass bottle with an aluminum foil liner. 
Solvents 
1. Water was purified by passing in succession 
through activated carbon filter, XAD-2 column 
(Chesler et al. 1976) and final ultrafilter. 
2. All other solvents—dichloromethane, MeOH, 
etc.—were distilled in all-glass distilla¬ 
tion apparatus. Tetrahydrofuran was di¬ 
stilled from freshly cut sodium, an important 
recommended procedure that prevents buildup 
of explosive peroxides. 
Septa (GC-Injection Port) 
1. Septa with high thermal stability were used: 
Thermogreen (TM) LB-1 Septum, SUPELCO, INC. 
2. The septa were stored in capped organic-free 
containers until use. They were inserted 
into the injection port using cleaned tools. 
This procedure made it unnecessary to precondition the 
septa after installation in the GC or GCMS. 
Field Sampling Procedures 
Water Extraction using Sep Pak Cartridge 
1. Luer-type syringe was fitted with a C13 Sep Pak 
(Waters Associates). 
2. A clean glass jar was immersed to obtain a 
subsurface water sample. 
3. This water was transferred into the barrel of 
the syringe. The plunger was inserted and the 
water was pushed through the C18 cartridge. 
4. Step 3 was repeated until the back pressure 
buildup, due to filtered particulates plugging 
the cartridge, prevented further concentration 
48 
