Zippo lighter fluid is petroleum ether, AKA colemans fuel, there are a few different brands, depending on the purity needed, test it, by placing a single drop on a mirror or glass slide and allow to evaporate.
Residue indicates oily inpurities.
Edit: a quick overview of common brands, Ronson is poor, leaves oily traces, Coleman's fuel, never used it myself, but its popular with tweakers who cook their own, so probably cheap and nasty
go with Vm&p naptha if you can find it, according to the hive, VM&P is the "Bee's knees"