User Guide

For an introduction to the application and use of Certified Reference Materials in absorption spectrophotometry

 
images
 
PRODUCT ENQUIRY
  
user
FURTHER PRODUCT INFORMATION 
& HOW TO ORDER

 

This reference is described in the European Pharmacopoeia as a resolution test for use in derivative spectroscopy.

When scanned in 2nd derivative mode against the methanol blank, the resulting spectrum should be as below:

In derivative spectroscopy, absorption spectra are transformed into first-, second- or higher-order derivatives. This technique facilitates the resolution of two or more peaks that overlap and become merged into a composite curve, and are represented by shoulders on that curve rather than as individual peaks. By calculating the derivative, the underlying individual spectra can be more readily identified. Probably the most used is the second order
i.e d2 A/dλ2.

When this reference material is scanned in 2nd derivative mode against the methanol blank, the resulting spectrum should be should be similar to that shown, with a small negative extremum  (   —>   ) at 285 nm between two larger negative  extrema at 261 nm and 268 nm.    

 

toluene in methanol

Toluene-in-Methanol

To meet the requirements of the Pharmacopoeia,  the ratio A/B should be greater than 0.2:

toluene-in-methanol

To meet the requirements of the Pharmacopoeia, the ratio A/B should be greater than 0.2. 

 

A Certificate of Calibration and Traceability and full instructions for use are provided with each Reference Material. Starna Scientific is accredited to both ISO 17034 (4001) as a Reference Material producer, and ISO/IEC 17025 (0659) as a Calibration Laboratory for optical reference measurements. Starna offers a Lifetime Guarantee on all its Reference Materials.