Hexane is an organic compound, a straight-chain alkane with six carbon atoms and has the molecular formula C6H14.
Hexane is a significant constituent of gasoline. It is a colorless liquid, odorless when pure, and with boiling points approximately 69 °C (156 °F). It is widely used as a cheap, relatively safe, largely unreactive, and easily evaporated non-polar solvent.
A typical laboratory use of hexanes is to extract oil and grease contaminants from water and soil for analysis. Since hexane cannot be easily deprotonated, it is used in the laboratory for reactions that involve very strong bases, such as the preparation of organolithiums. For example, butyllithiums are typically supplied as a hexane solution.
Hexanes are commonly used in chromatography as a non-polar solvent. Higher alkanes present as impurities in hexanes have similar retention times as the solvent, meaning that fractions containing hexane will also contain these impurities. In preparative chromatography, concentration of a large volume of hexanes can result in a sample that is appreciably contaminated by alkanes. This may result in a solid compound being obtained as an oil and the alkanes may interfere with analysis.
Hexane is used to extract edible oils from seeds and vegetables, as a special-use solvent, and as a cleaning agent. Acute (short-term) inhalation exposure of humans to high levels of hexane causes mild central nervous system (CNS) effects, including dizziness, giddiness, slight nausea, and headache.
| Items | Unit | Actual | Spec. | Test Method |
|---|---|---|---|---|
| Saturated Hydrocarbons | % by wt. | 99.97 | ASTM D3054 | |
| C6H14 | % by wt. | 80 | ASTM D5134 | |
| Unsaturated Hydrocarbons | Mg Bromine/ 100g Hexane | 50 | 100 | ASTM D1492 |
| Total Sulfur | ppm by wt. | 1 | ASTM D4045- DIN 51 751 | |
| Benzene | ppm by vol. | 50 | 100 | ASTM |
| IBP | °C | 63 | ASTM D1078 DIN 51751 | |
| FBP | °C | 70 | ASTM D1078 DIN 51751 | |
| Density at 15 °C | g/cm³ | 0.64-0.685 | ||
| Alcohols, Ketones, Aldehydes, Acids | mmole RCOOH/ 1 diluent | 1 | Titration with Acridine | |
| Aromatics | ppm by wt. | 50 | 100 | ASTM D3054, D5134 |
| Cyclohexane | % by wt. | 1.5 | 2 | ASTM D3054, D5134 |
| Water | ppm by wt. | 50 | ASTM E203 | |
| n-Hexane | % by wt. | 60 | 56 | ASTM D5134 |
| i-Hexane | % by wt. | 30-40 | ASTM D5134 | |
| Methyl Cyclopentane | % by wt. | 8 | 12 | ASTM D3054, D5134 |
| Chlorides | ppm by wt. | <1 | ||
| UV Absorption Extinction | at 240 – 280 nm | 0.15 | 0.15 | ASTM D2008 |
| UV Absorption Extinction | at 280 – 400 nm | 0.05 | 0.05 | ASTM D2008 |