INTERDIVISION COMMITTEEAL WORKING PARTY ON HARMONIZATION
OF QUALITY ASSURANCE SCHEMES FOR ANALYTICAL LABORATORIES
Number: 501/7/95
Series: Harmonization
Title: Protocol for the Use of Recovery Factors
Coordinator(s): R.
Wood and M. Thompson
Completion Date: 1998
Objective:
The use of recovery factors is a controversial issue among
analytical chemists. The problem is most significant in the determination
of pesticides or veterinary residues in complex matrices such as foodstuffs
and in certain cases environmental materials e.g. soil). Typically, such methods
of analysis rely on transferring the analyte from the complex matrix into
a much simpler solution that is to be presented for instrumental determination.
However, the transfer procedure results in losses of analyte. If an estimate
of the true concentration is required (as it usually is - as it is usually
compared to a statutory or contractual limit) compensation for these losses
should be made in the calculation. There is no standardization between approaches
to the use of recovery factors, an area which is becoming of increasing legislative
importance. Many procedures universally regarded as valid practice when correctly
executed involve compensation for analyte losses. The objective of this project
is to bring together the different approaches and to make definitive recommendations
as to the "best practice". These would be in the form of a Protocol developed
under the auspices of IUPAC and which would be adopted and used by various
standardization organizations, governments and regulatory bodies.
Progress:
Project Completed - Report reference: Pure
Appl. Chem.
71(2), 337-348, 1999.
