Question

Compare the detection limits and applications of the four typical GC detectors (FID, TCD, ECD, and MSD)

Answer 1

TCD ----> Detect any compound but sensitivity is poor.

FID ------> It is sensitive for the compound containing carbon. Sensitivity is better than TCD.

ECD ------> Capable of high sensitivity detection of electrophilic compounds. Simply stated electrophilic compounds contains halogen elements (Cl, Br, F, I) . There may also be some sensitivity for the cmpounds not contaning halogen elements.

APPLICATION::: FID= > A flame ionisation detector is a scientific instrument that measure analyte in gas stream and also widely used in the petrochemical, pharmaceutical and gas markets.

TCD= > It is a technique used to analyze inorganic gases ( Ar,N ₂ ,H ₂ ,CO ₂,etc) and small hydrocarbon molecules. It compares thermal conductivity of two gas flows - pure carrier and sample . The change in this thermal conductivity are sensed as a change in electrical resistance are measured.

ECD= > This technique is basically analyze halogenated compounds in pharmaceutical companies.

MSD= > Determination of pesticides residue on baby food are evaluated from exposure to the environmental contamination.