WHO publishes Draft Working Document on Chromatography

The World Health Organization (WHO) has published a draft proposal for inclusion in The International Pharmacopoeia. The new chapter 1.14.1 Chromatography shall replace the chapters 1.14.1 Thin-layer chromatography, 1.14.4 High-performance liquid chromatography and 1.14.5 Gas Chromatography.

The first draft working document was prepared based on the internationally-harmonized text developed by the Pharmacopoeial Discussion Group (PDG).

The following aspects are covered:

• Introduction: The introduction contains a short section on the definition of chromatography.
• Definitions: The section contains definitions and calculations of common parameters, e.g.
  - Distribution constant
  - Dwell volume
  - Peak-to-valley ratio
  - Plate height 
  - Plate number
  - Relative retardation 
  - Resolution
  - Separation factor
  - Signal-to-noise ratio
  - Symmetry factor
  - System repeatability
• System suitability: In this section, generally applicable requirements for system suitability are given. Only liquid chromatography and gas chromatography are covered.
• Adjustment of chromatographic conditions: The extent to which the various parameters of a chromatographic test may be adjusted without fundamentally modifying the pharmacopoeial analytical procedures are listed.
• Quantitation: The quantitation approaches that may be used in general texts or monographs are described.
• Other considerations: The new chapter concludes with some general aspects on
  - Detector response
  - Interfering peaks
  - Measurement of peaks
  - Reporting threshold

The draft working document (QAS/21.905) is available as a PDF file on the WHO homepage. Comments can be submitted until 25 March 2022.