Question

1. Which method of GC gives the highest number of theoretical plates and hence the best resolution/separating power?
a. Open tubular GC
b. Packed Column GC

2. What is the most appropriate detector for the following analytes?

"Electron Capture", "Thermal Conductivity", "Thermionic" - Halogenated Compounds
"Electron Capture", "Thermal Conductivity", "Thermionic" - Phosphorous and Nitrogen compounds
"Electron Capture", "Thermal Conductivity", "Thermionic" - Mixture of gases.

Answer 1

Answer1

Gas chromatography is a separation technique used to separate mixture of volatile substances.

it can be done in two ways that are open tubular gas chromatography and packed column gas chromatography

open tubular gas chromatography is the process in which there is  finely divided inert solid support material coated with liquid stationary phase.

packed column gas chromatography  is the process in which there is capillary tube whose walls are coated with liquid stationary phase

a) No. of theoretical plates depends on various factors among them the length of column is one of the important factor. As, the length of open tubular is very high in comparison to Packed column so the no. of theoretical plates is high in open tubular gas chromatography.

b) Resolution is the measure of clarity of two distinct point as distinct with respect to their distance. Because of greater length the resolution of open tubular gas chromatography is higher in comparison to packed column gas chromatography