Spectroscopic identification in the “real world”

Columns

01 Apr 2009

Tony Davies^a and Tom Fearn^b
^aNorwich Near Infrared Consultancy , 75 Intwood Road, Cringleford, Norwich NR4 6AA, UK
^bDepartment of Statistical Science, University College London, Gower Street, London WC1E 6BT, UK

Bankers’ pensions, Government borrowing or Spectroscopy Europe columnists, the watchword for 2009 appears to be controversial! In the previous version of this column, Tony Davies (the younger) was being controversial about education and in this issue I am being controversial about one of the current applications of chemometrics to the use of spectroscopy in industry.

In particular I am unhappy about the way in which chemometrics is being applied for identity testing of pharmaceutical raw materials. The operational deployment of the method produces an unknown risk that an incoming, incorrectly labelled raw material would not be detected as an error. This is known as a “false positive”.
I need to make it clear that my collaborator (Tom) and I are not in complete agreement. Tom agrees that an error could occur but he thinks that the risk is probably quite small and the only viable alternative is to do nothing which is certainly unacceptable. My views are that:

Everyone using the method should be aware and admit the potential risk of a false positive.
Every batch in a delivery should be tested by a rapid method, all must be identified as the label compound and at least one container should be tested by a “compendium method” and positively identified as the label compound.
Research should be undertaken to find methods for estimating the risk of a false positive occurring.

Tony Davies

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