222 

 mm i.d. Carbowax column (df=0.25 jim). Analyses involving the comparison of 



subjects were performed with two ramp programs, depending upon the column 

 employed. The columns were a 25 m x 0.20 mm i.d. HP5 FSOT column (df=0.33 

 ^im) or a HP-FFAP 25 m x 0.20 mm i.d. FSOT column (df=0.33 ^m). For 

 experiments conducted with the HP5 column (35 min run time), the GC ramp 

 consisted of a-1.0 min hold at 40°C followed by a 11 min ramp at 17°C/min, and then 

 a hold at 220°C for 23 min. The transfer line was concurrently ramped from 50°C 

 to 220°C at 20°C/min over 8.5 min and held at 220°C for the remainder of the 

 analysis. The ramp program for the FFAP column (45 min run time) consisted of 

 a 1.0 min hold at 40°C followed by an 18 minute ramp at ll°C/min to 236°C, and 

 then a hold for 26 min at this temperature. The transfer line was ramped from 50°C 

 to 236°C at 23°C/min for 8 min and held at 236°C for the remaining 37 min. The 

 final ramp which was used is described in the experimental section covering the five- 

 day comparison of bio-assay to GC/MS. 



Acquisition of PPINICI data employed methane reagent gas at 1660-1690 

 mtorr (indicated) pressure. The ion source and manifold temperatures were 150°C 

 and 70°C, respectively for CI and HCC and 70''C, respectively for EI. The electron 

 energy for CI experiments was 100 eV and for EI, 70 eV. The third quadrupole was 

 typically scanned with a scan time of 1 s per scan for PPINCI and 2 s per scan for 

 EI data (except for the five-day comparison study). The filament emission current 

 was set at 200 ^lA. The conversion dynode was set at +5 kV for positive ion CI and 

 EI, and -5 kV for negative ion CI. The electron multiplier was set between -1000 V 



