220 

 Experimental 



Identification of Emanations by CI and EI MS 



Cryo- focusing GC/MS 



The results from these analyses are tabulated later in this chapter. The list 

 of components was derived from the analysis of cryo-focused volatiles from handled 

 glass beads. The cryo-focusing process involved heating of beads in the GC injection 

 port to desorb volatiles. A Varian 3400 GC fritted glass injection insert was inserted 

 reversed into the injection port. This allowed for up to 12 beads to be placed 

 between the frit (located approximately halfway down the insert) and the GC septum 

 sealing the injection port. The frit kept the beads from dropping down onto the 

 column entrance and provided a means for volatile emanations to be loaded onto the 

 column; the column entrance extends up into the injector insert and is located below 

 the frit. Additionally, the injection port was operated in an entirely splitless mode 

 for the duration of the experiment providing essentially only one exit for volatiles, 

 i.e. through the column. 



Beads were rubbed for 5-15 min prior to placing into the injector insert. The 

 initial experiments employed eight beads handled by the author of this dissertation; 

 later experiments (discussed in the comparison sections) involved from two to five 

 beads handled by Mr. Dan Smith, Mr. Carl Schreck, and Mr. Ken Posey, all of the 

 USDA. After loading the beads into the insert, the insert was placed into the 

 injection port held at 25°C to minimize sample loss from evaporation. The cap, 



