Toluene in Hexane (265 – 270 nm)

A solution of toluene in hexane is the most widely used reference for qualifying the Spectral Bandwidth (SBW) of a UV spectrophotometer. It is accepted for this purpose by most Pharmacopoeias and Standardisation Bodies.

It can be used with spectrophotometers having spectral bandwidths of 3 nm or less.

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Toluene In Methanol (265 – 270 nm)

This reference was described in earlier editions of European Pharmacopoeia (EP) Chapter 2.2.25 for use as a resolution check in Derivative Spectroscopy.

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Benzene Vapour (230-270 nm)

This reference is useful as a resolution check for instruments with spectral bandwidths less than 1 nm. Benzene vapour has characteristic peaks that may or may not be displayed, depending on the SBW of the instrument.

Note: Benzene vapour is not suitable for use with photodiode array spectrophotometers. 

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