Question

Separating and Identiying Mixtures by Gas Chromatography Lab 3. For each parameter listed, explain whether or not a change in the parameter will have an effect on the retention time of a compound. (a) injector temperature (b) column temperature (c) detector temperature (d) length or type of column (e) size or injected sample (f) detector attenuation Please explain. Thank you so much.

Answer 1

a- in gas chromotography the sample should be converted into the gas phase. To do this injector temperature should be high.

b- column temperature is very important here. If column temperature is very high it speeds up all the components those go through the column. Therefore column temperature should be at a medium rate then some components will condense depending their boiling points.

c- detector temperature should be at a range that can oonize the compund which is coming through the column. At detector when the compund is ionised due to the heat of the flame positive ions will gain electron from cathode and they will neutralize. Negative ions will move to the cathode.

d- length of the column should be at least about 4m high becuse higher the length of the column higher and better the seperation

e- sample size should be small because it should easily turn into gas phase. And the injected sample should beore volatile.

f- if the amount of sample passes through the detector is high,the signal is very clear