Table 1: Example pipetting scheme for the preparation of the calibration samples; concentration range 2 to 20 μg tetrachloroethene/L exhaled air.

NumberCalibration solutionsCalibration samples
Conc. stock solution II (mg/L) stock solution II (μL) final (mL)Conc. (µg/L) calibration solution (µL) gas sampling tube (mL)Mass (µg)Conc. (µg/L)

193.9401037620037.4330.07512.0
293.9801075120037.6680.15024.0
393.912010112720037.6390.22546.0
493.916010150220037.5240.30058.0
593.920010187820037.5730.375610.0
693.924010225420037.4860.450712.0
793.928010262920037.5440.525814.0
893.932010300520037.5930.601016.0
993.936010338020037.5980.676118.0
1093.940010375620037.6610.751219.9