Model FI53-02

The process of ionization which occurs in organic compounds when the carbon- carbon bond is broken via a thermal process in the flame that results in the formation of carbon ions. These ions are collected in the flame by applying a positive potential to the FID jet and the ions are pushed to the collection electrode where the current is measured. The response (current) is proportional to the concentration and is measured with an electrometer/amplifier. An FID consists of a combustion/ion chamber, a flame, a voltage source for the accelerating electrode (usually applied to the jet) and an amplifier ca-pable of measuring down to one to one picoamperes full scale. The FID is a mass sensitive detector, the output of which is directly proportional to the ratio of the compound’s carbon mass to the total com-pound mass. Thus, the sample is destroyed in the flame.