Hydrocarbons
No ambient air quality analysis is complete without an accurate quantitation of the toxic organic volatile hydrocarbons. The typical gas standard used in calibrating such an analysis is a mixture of paraffins/BTEX in nitrogen. This chromatogram illustrates how the detector's sensitivity to the air peak is suppressed when argon is added as a dopant. It also shows the PDD's remarkable sensitivity to a 30 ppb calibration mixture.
Courtesy of Scott-Marrin, Inc., John Marrin, president
| Run conditions | |
|---|---|
| Sample | 250 µl of a 30 ppb paraffins/BTEX blend in nitrogen |
| Detector mode | Argon photoionization |
| Discharge gas | 1.5% Ar (mole) in helium, 30 mL/min |
| Dopant gas | None |
| Detector temp | 40°C |
| Column | 100% dimethylpolysiloxane, 20m x 0.53mm |
| Column temp | 30°C for 1 min to 110°C at 8°min |
| Attenuation | 2 x 10-1 |