2011/7/6 · Reagent STD A added to 20 mL crimp top headspace vial Concentration (ng/mL headspace) Low Level 4 1 µL 20 3 0.75 µL 15 2 0.50 µL 10 1 0.25 µL 5 Blank 0 µL 0 High Level 5 62 µL 1,240 4 31 µL 620 3 6.2 µL 124 2 0.78 µL 15.5 1 0.25 µL 5 Blank 0 µL 0