Single-point absorbance checks on ultraviolet spectrophotometers are no longer acceptable leading to increased demand for sets of sealed potassium dichromate cells
Single-point absorbance checks on ultraviolet spectrophotometers are no longer acceptable in many pharmaceutical laboratories, which now require a multi-point validation of the absorbance scale and linearity.
According to John Hammond, technical and marketing manager for Starna brand analytical products at Optiglass, this has led to a significantly increased demand for sets of sealed potassium dichromate cells.
These certified reference materials provide a convenient and recognised validation method and are traceable to Nist standard reference materials.
Five different potassium dichromate concentrations solvated in 0.001M perchloric acid, plus a blank solution, are prepared according to Nist special publication 260-54, and permanently sealed by heat fusion in far UV quartz cells.
They are then calibrated against primary references in an ISO/IEC 17025 environment.
Instrument linearity can be established at four UV wavelengths: 235nm, 257nm, 313nm and 350nm.
Full documentation on measurement, handling and storage is provided with each set of CRMs.
