Document wr6xyLwoeb8w14yoZqe12kqME

t AR226-2037 w jv M v>uivv^mUi^.w iw^s1'^ v| * . :. H- 3 PECKSR 08/06/98 12:16 AM To: SZAKATBK. MILLERSR , HALBERRM co: ESTILUO , 21PFEL, MILLERW, MAYLESM , PARSONMA Subject: air C8 recheck As Shown in the Table below, all air samples collected 7-29-98 appear to contain appreciable levels of C-8 except for the blank. These samples were analyzed with fresh reagent (from a new shipment that arrived late Wednesday). In addition to the "blank" Tenax tube, three additional blanks were examined. All blanks showed essentially clean baselines which verify the purity of the reagent. The GC response at retention time of "3.7 minutes (corr C8 pk) is shown to emphasize the levels of C8 observed. Table 1: C-8 in Air corr Liters SAMPLE LOCATION C8 pk A smoking area; 162 roof 18547 B1 blank tube 1309 Cl top of SW stairs, unit side 37058 of air 50.7 44.2 52.3 ug C8 0.738 0 1.545 D1 SE rail 32870 45.6 1.363 E mid-rail, North 23812 48.2 0.968 rapb C8 0.82 0 1.66 1.67 1.13 Table 2: Calibration results corr Standard blank (0 ug) 0.1 ug standard 0.5 ug standard 1.0 ug standard C8 pk. 693 4090 14539 23797 Slope: 22948 intercept: 1600 R"2: 0.989 It should be stressed that although the electron capture (ECD) used in this GC method is extremely sensitive for fluorinated species (e.g. "C-8"), it is incapable of providing positive (qualitative) identification of analytes. It is theoretically possible that the response (peak) interpreted as "C-8" is another substance (or mixture) which co-elutes with C-8. Recommend additional samples be collected ASAP. Duplicates should be obtained where possible as we are still working to improve robustness RJZ012742 EID937318 of this method and understand run-to-run variations, SP 'i . . EID937319 RJZO12743