User Guide

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



The most widely used Reference Material for qualifying the absorbance scale of UV-visible spectrophotometers (235 - 430 nm). It is accepted for this purpose by most Pharmacopoeias and Standardisation Bodies, including:

European Pharmacopoeia
Deutsches Arzneibuch (German Pharmacopoeia)
United States Pharmacopoeia
American Society for Testing and Materials
Therapeutic Goods Administration (Australia)
British Pharmacopoeia

These references consists of Potassium Dichromate solvated in 0.001 M perchloric acid and permanently sealed by heat fusion into 10 mm UV-quality quartz cells, and a blank cell containing 0.001 M perchloric acid.
This solution gives a spectral scan containing characteristic peaks at 257 nm and 350 nm, and troughs at 235 nm and 313 nm.


RM-0204060810 B K


Within the concentration range 0 - 240 mg/l, if the absorbance scale of the spectrophotometer is linear, the measured absorbances of a series of potassium dichromate concentrations will be a linear function of concentration. 12 solutions are available covering this concentration range in 20 mg/l steps.


A 600 mg/l solution is also available, certified at 430 nm for use in the visible region .



A Certificate of Calibration and Traceability and full instructions for use are provided with each Reference Material. Starna Scientific is accredited to both ISO Guide 34 (4001) as a Reference Material producer, and ISO 17025 (0659) as a Calibration Laboratory for optical reference measurements. Starna offers a Lifetime Guarantee on all its Reference Materials.