Petroleum ether, also known as benzine, VM&P Naphtha, Petroleum Naphtha, Naphtha ASTM, Petroleum Spirits, X4 or Ligroin, is a group of various volatile, highly flammable, liquidhydrocarbon mixtures used chiefly as nonpolar solvents. Chemically, it is not an ether like diethyl ether, but a light hydrocarbon.
Petroleum ether is obtained from petroleum refineries as the portion of the distillate which is intermediate between the lighter naphtha and the heavier kerosene. It has a specific gravity of between 0.6 and 0.8 depending on its composition. The following distillation fractions of petroleum ether are commonly available: 30 to 40 °C, 40 to 60 °C, 60 to 80 °C, 80 to 100 °C, 80 to 120 °C and sometimes 100 to 120 °C. The 60 to 80 °C fraction is often used as a replacement for hexane. Petroleum ether is mostly used by pharmaceutical companies in the manufacturing process. Petroleum ether consists mainly of pentane, and is sometimes used instead of pentane due to its lower cost. Petroleum ether is not technically an ether.
Benzine should not be confused with benzene or benzyne. Benzine is a mixture of alkanes, e.g., pentane, hexane, and heptane, whereas benzene is a cyclic, aromatic hydrocarbon, C6H6. Likewise, petroleum ether should not be confused with the class of organic compounds called ethers, which contain the R-O-R functional group.
During the Second World War some extermination camps experimented by killing people with benzine injections
Additional:
Ligroin is a refined saturated hydrocarbon petroleum fraction similar to petroleum ether used mainly as a laboratory solvent. It predominantly consists of C7 through to C11 in the form of about 55% paraffins, 30% monocycloparaffins, 12% alkylbenzenes, and 2% dicycloparaffins. It is nonpolar. Generally laboratory grade ligroin boils at 60 to 90 °C.
