Moses is right. The active part is the nitrite, and the amyl, butyl, isobutyl, isoamyl, isopropyl or cyclohexyl are of lesser importance and mainly influence boiling point / volatility.
I have no personal experience with poppers, but I know the smell of the pure chemical. The few times I witnessed others using poppers, there was smell of decomposition products.
As far as I can judge, the problem is stretching the active ingredient (with any low smell, high boiling oil) and decomposition. Nitrites are unstable and decompose slowly at ambient temperature.