Nujol

Nujol
Other names mineral spirits, adepsine oil, alboline, glymol, liquid paraffin, paraffin oil, saxol, USP mineral oil
Identifiers
CAS number	8042-47-5 N
Properties
Appearance	colourless liquid
Boiling point	179-210 °C (452-483 K, 354-410 °F)
Structure
Dipole moment	zero
Hazards
R-phrases	R36 R37 R38
Flash point	135 °F
N (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Nujol is a brand of mineral oil by Plough Inc., cas number 8042-47-5, and density 0.838 g/mL at 25 °C, used in infrared spectroscopy. It is a heavy paraffin oil so it is chemically inert and has a relatively uncomplicated IR spectrum, with major peaks between 2950-2800, 1465-1450, and 1380–1370 cm⁻¹. The empirical formula of Nujol is hard to determine exactly because it is a mixture but it is essentially the alkane formula C_nH_(2n + 2) where n is very large.

To obtain an IR spectrum of a solid, a sample is combined with Nujol in a mortar and pestle or some other device to make a mull (a very thick suspension), and is usually sandwiched between potassium- or sodium chloride plates before being placed in the spectrometer. For very reactive samples, the layer of Nujol can provide a protective coating, preventing sample decomposition during acquisition of the IR spectrum. When preparing the sample it is important to keep the sample from being saturated with Nujol, this will result in erroneous spectra since the Nujol peaks will dominate, silencing the actual sample's peaks.

External links

MSDS data sheet

Nujol's historic use as an alternative medicine