223 

 and -1200 V. Prior to analysis the instrument was tuned with PFTBA as previously 



mentioned and blanks (appropriate number of beads without sample) were recorded. 



Purge and trap GC/MS 



These experiments involving microscale purge & trap mainly employ samples 

 from the author of this dissertation; two samples, one from handled beads and one 

 involving placing the left hand in a Tedlar bag, were collected from Mr. Matt Booth 

 of Environmental Science & Engineering (ESE). The bead method involved 

 handling 200-250 glass beads for 10 min, and transferring them to a 100 mL round 

 bottom flask, as discussed previously (Chapter 2). The round bottom flask was 

 attached to the system via a 1/2" Cajon fitting to 1/4" Swagelok, further reduced to 

 a 1/8" Swagelok fitting. Alternatively, sampling was accomplished by placing the left 

 hand in a Tedlar bag and fastening the bag around the wrist with a rubber band; the 

 Tedlar bag was simply attached by a 1/8" Swagelok fitting. The 1/8" Swagelok was 

 connected to a port on an ELA2010 canister manifold (Entech Laboratory 

 Automation). 



The canister manifold allowed for 70-100 mL of volatiles and residual air to 

 be sampled by the ELA2000 concentrator. The concentrator consisted of three 

 stages. The first stage employed a dryer with a gradient of large to small beads. 

 This served to remove most of the water in the sample. During concentration, this 

 stage is set to -160''C for three minutes and heats up to -16°C as sample is 

 transferred to the second stage. The second stage in these experiments was a Tenax 

 trap. During concentration, the trap was set to -20°C; it was then heated to 156°C 



