User Guide

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

Two methods for the qualification of Stray Light are described in ASTM E387. Until May 1st 2015, all major Pharmacopoeias recommended the Specified Wavelength Method. On that date the US Pharmacopeia issued its Chapter <857> recommending the alternative Liquid Filter Ratio Method, also known as the Meilenz Method. This method is simpler to use with high-performance spectrophotometers, especially those with double monochromators. Chapter <857> is mandatory from May 1st 2016. The Specified Wavelength method is currently still available for the USP and is also recommended by the following authorities:

  • European Pharmacopoeia,EP
  • British Pharmacopoeia,BP
  • Deutsches Arzneibuch (German Pharmacopoeia),DAB
  • Therapeutic Goods Administration (Australia),TGA
  • Japanese Pharmacopoeia,JP
  • Pharmacopoeia of the Peoples Republic of China, PPRC

Stray Light Cut-off Filters – Specified Wavelength Method

A range of liquid cut-off filters that allows stray light to be checked at wavelengths from 200 nm to 390 nm.

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Stray Light Cut-off Filters – Filter Ratio Method

These Reference Materials are described in the US Pharmacopeia (Chapter <857> to qualify the Stray Light (or Stray Radiant Energy) of ultraviolet spectrophotometers. A range of materials covers wavelengths from 190 nm to 385 nm

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