Nujol

Nujol
Identifiers
CAS number 8012-95-1 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 8012-95-1, 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 CnH(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 CAS Number for Nujol