Testing the Efficiency and Uncertainty of sample processing for analysis of food contaminants

Introduction:

It must be appreciated that the values of analytical determinations are dependent on the procedures used to estimate these values. In particular, the estimate of a value may be dependent upon the method of analysis used, but is always dependent on the method of sampling used to verify compliance with the specification. It is important to appreciate the influence that methods of analysis and sampling may have on the judgements that may be made with regard to the compliance of a lot with respect to a given specification. Without common and uniform criteria for methods of analysis and sampling procedures and their common application and interpretation, there will be different judgements as to whether any particular lot is in compliance with the specification.
This CRP therefore is focusing on the factors influencing the variability of analytical results. This concerns the sampling of test items and the distribution of residues within a batch, even on single (big) fruits. Further more sample homogenisation at different temperatures and processing conditions is investigated regarding the impact on the degradation of target compounds during the analytical procedure.

Objective:

• To determine the efficiency of various sample processing equipment, and to estimate the uncertainty of sample processing.
• To determine the stability of analytes during sample processing.
• To facilitate compliance with the requirements of ISO 17025 Standard, and thereby promote testing compliance with Codex and/or national limits according to current international requirements.

Expected Outputs:

• Validated sample processing methods and equipment.
• Data on the efficiency of different types of sample processing equipment.
• Determined particle size distribution in the homogenised samples and the maximum acceptable particle size not affecting the precision of sample processing.
• Typical uncertainty values for sample processing of representative commodities.
• Information on the stability of pesticides under processing conditions.
• Publications of the results in a special issue of a peer-reviewed scientific journal and through the Internet, to accelerate laboratory accreditation in Member States.
• Accelerated laboratory accreditation in Member States.
• Proposals for the inclusion of the results into the recommended procedures of the Codex Committee on Pesticide Residues.

Activities:

• The First Research Coordination Meeting was held in Seibersdorf, Austria, from 15-20 July 2002.
• The Second Research Coordination Meeting was held in Madurai, India, from 10-15 January 2005.
• The Final Research Coordination Meeting will be held in Neuquen, Argentina, from 24-28 September 2007.

Reports:

• Report of the First RCM, Seibersdorf, Austria, 15-20 July 2002.
• Report of the Second RCM, Madurai, India, 10-15 January 2005. [Download pdf]

Project Officer:

J. Brodesser