in gas chromatography, why do E1 and E2 give different peaks (areas) though it's the same compound??

Question

dehydration of a secondary alcohol proceeds readily with the presence of strong acid and proceeds with E1 mechanisms. Removing product from chemical system at equilibrium shifts the equilibrium in the direction favoring the formation of the products.

I carried out a dehydration in reaction tube connected to a gas collector so that product will continously escape out of reaction mixture as it is formed. The collected gaseous product was anaylzed using gas chromatography which show peaks. With the relative area of peaks, we are able to calculate percentage composition of product mixture.

for the second part, I proceeded with the base-induced dehybromination reaction which goes through E2 mechanism.

1-butene was one of the compounds in the mixture and the peak was low (percent composition was low) but in E1, the peak (percent composition) was very high in E2.

So depending on the mechanism, it produces different amounts of the products since in one we're using acid and the other we're using a base and I am not sure how and why it gives different amounts.