The document discusses gas chromatography and the flame ionization detector. It explains that gas chromatography separates components from a crude drug using an inert gaseous mobile phase moving through a column coated with a liquid stationary phase. The flame ionization detector is then described as one of the most widely used detectors in gas chromatography. It works by mixing the effluent from the column with hydrogen and air, igniting it electrically, and measuring the resulting current which is proportional to the number of carbon atoms entering the detector. The FID is highly sensitive, easy to use, and responds well to most organic compounds, making it a useful general detector for analyzing organic samples.

1. GAS CHROMATOGRAPHY
FLAME IONISATION DETECTOR
MADE BY – SAURABH PUNIA
M-PHARM 1ST YEAR
SCHOOL OF PHARMACEUTICAL SCIENCES CSJMU,KANPUR

2. • Gas chromatography – “It is a process of separating component(s)
from the given crude drug by using a gaseous mobile phase.”
• It involves a sample being vaporized and injected onto the head of the
chromatographic column. The sample is transported through the column
by the flow of inert, gaseous mobile phase. The column itself contains
a liquid stationary phase which is adsorbed onto the surface of an inert
solid.

3. INSTRUMENTATION
1. Carrier gas
2. Sample injectionport
3. Columns
4. Detectors -
 Thermal conductivity (TCD)
 Electroncapture detector(ECD)
 Flame Ionization detector(FID)
 Flame photometric(FPD)

5. DETECTOR
• The eluted solute particles along with the carrier gas exit from the column and
enter into the detector.
• Properties of an ideal detector
⚫ Sensitive
⚫ Operate at high T (0-400 °C)
⚫ Stable andreproducible
⚫ Fastresponse
⚫ Simple(reliable)
⚫ Non destructive
⚫ Uniform response to all analytes

6. FLAME IONIZATION DETECTOR
• The flame ionization detector(FID) is one of the most widely used
detector in gas chromatography.
• It is used with a burner.
• The effluent from the column is mixed with hydrogen and air and
then ignited electrically.
• A potential of a new hundred volts is applied across the burner tip and
a collector electrode located above the flame. The resulting current (
approx. 10-12 ) is amplified for the measurement.

8. • The flame ionization detector responds to the no. of carbon atoms
entering the detector per unit of time, it is a mass sensitive , rather than
a concentration sensitive device.
• Functional groups, such as carbonyl, alcohol, halogen and amine, yield
fewer ions or none at all in a flame. This makes the FID unsuitable.
• The detector is insensitive toward non combustible gases such as H2O
CO2 and SO2 and NO2. This properties make the flame ionisation
detector a most useful general detector for the analysis of most organic
samples.
• The flame ionization detector exhibits a high sensitivity (approx.10-
13g/s).
• It is easy to use. It causes destruction of sample which is main
drawbacks.