n-Heptane

About This Product

n-Heptane, formula C7H16 and CAS number 142-82-5, is the straight-chain seven-carbon paraffin. It is a clear, colourless, volatile liquid boiling at about 98 °C, insoluble in water and an excellent solvent for oils, fats, waxes and non-polar resins. Two facts give n-heptane its particular markets. The first is that it defines zero on the octane scale: pure n-heptane knocks readily, and blended with isooctane, which defines 100, it forms the primary reference fuels against which gasoline octane is measured. The second is toxicology. Unlike n-hexane it is not metabolised to a neurotoxic diketone, and it sits in the lowest-concern class of the ICH Q3C guideline for residual solvents, so pharmaceutical manufacturers routinely substitute it for hexane in extraction, crystallisation and washing steps. For those uses the limits that matter are the ones this grade controls: total aromatics at 50 ppm, sulphur at 1 ppm, water at 50 ppm and a boiling range between 94 and 99 °C. It is used as a pharmaceutical process and crystallisation solvent, in octane-rating reference fuels, as an extraction solvent for natural products, in adhesives and rubber cements, and as a laboratory and chromatographic solvent. Bio Green Chem supplies n-heptane at 99 percent minimum, with a 97 percent grade also available, to specification on Saybolt colour, boiling range, density, bromine index, aromatics, sulphur and water, in 137 kg drums or ISO tanks. It is highly flammable and an aspiration hazard; handle to the safety data sheet.