Latest version of the European Pharmacopoeia notes that: 'suitable certified reference materials may also be used' - John Hammond contends that only externally sourced CRMs are good enough
"Don't risk it - use only CRMs".
This was the important message from John Hammond of Optiglass UK, when addressing the annual meeting of the NPL's Optical Radiation Measurement Club and explaining the implications for spectrophotometric measurements of the latest version of the European Pharmacopoeia.
In its technical revision 5.2, the Pharmacopoeia introduces a new 600mg/l potassium dichromate reference material for the qualification of UV/Visible spectrophotometers.
This solution is used for control of absorbance at 430nm.
Also revised is the use of 12g/l potassium chloride solution for stray light measurement at 198nm.
For the control of these and other parameters (eg, wavelength, resolution), the Pharmacopoeia notes that: 'suitable certified reference materials may also be used'.
In defining 'suitable' reference materials, Hammond contends that only externally sourced CRMs produced within an accredited environment can provide the necessary independent evidence of control and have the capability to isolate the instrument qualification from the laboratory environment.
ISO/IEC 17025 accreditation also provides a third party endorsement of the process and certification that produces the CRMs.
Hammond is a recognised authority in this field and is technical and marketing manager for analytical products at Optiglass, which produces a range of certified reference materials under the internationally respected Starna brand.
