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.
A range of 12 solutions covers absorbance values from 0.2 A to 3.6 A at wavelengths from 235 nm to 350 nm. An additional reference is available calibrated at 430 nm (absorbance 0.95 A). These references are available singly or in any combination and as convenient sets, each of five references and a blank solution, covering low (up to 1.5 A) and high (up to 3.0 A) absorbance ranges. They are also used in Starna’s UV Instrument Qualification Kits, which contain all you need to comply with Pharmacopoeia requirements.
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.