Materials that are used for proficiency testing become well characterized by the data generated from these programs. These consensus reference materials can be very valuable because they may be the only reference material available for certain analytes, particularly for food contaminant testing. In addition, the data generated in proficiency testing programs may represent the first step on the way to the material becoming a certified reference material. Conversely, certified reference materials may be included in the samples used in a proficiency program to benchmark the laboratories participating. Chair: Bill Ikins, PhDCorporate Chemistry Director Silliker Laboratories Homewood, IL Speakers: Andree Lamberty Topic: Demands from Proficiency Testing on the Characteristics of Reference Materials Proficiency testing is a powerful tool in quality assurance for evaluating laboratories' performance. It allows laboratories to compare their competence with that of other laboratories for internal evaluation as well as for demonstration to third parties e.g. accreditation bodies. To fulfil these goals the materials provided in proficiency testing schemes must respond to certain characteristics. The required specifications and the information will be discussed. Reference materials fulfil these requirements. The "family of reference materials" will be presented and the advantage of using certified reference materials in proficiency schemes will be highlighted.
Topic: Dietary Supplement Proficiency Testing: NIST Pilot Program The National Institute of Standards and Technology (NIST) has established a Dietary Supplement Laboratory Quality Assurance Program in collaboration with the National Institutes of Health (NIH) Office of Dietary Supplements (ODS). The program is growing rapidly. In February of 2007 samples for the pilot exercise were sent to 19 laboratories and in April of 2008 samples for the second exercise were sent to 34 laboratories. The intent of this program is to enable participants to improve the accuracy and precision of their analyses for nutrients, marker compounds, toxic elements, and/or pesticides in dietary supplement ingredients and finished products. Participants in this program receive three to five sets of samples, including Standard Reference Material controls, twice a year. Following the close of the exercise, participants receive reports presenting their results relative to those of other participants and to the expected values, as well as a certificate demonstrating their performance during the one-year cycle. Samples, laboratory performance, and future plans will be discussed.
Topic: Demands Surplus test materials from food chemistry proficiency testing The commercial proficiency testing (PT) scheme in the food chemistry area called FAPAS? will have run some 230 rounds involving 1600 participants from 65 countries world-wide during 2008. This scheme has a wide coverage of parameters of interest ranging from the relatively simple such as proximates (moisture and ash), through to the moderately demanding such as mycotoxins, pesticides and veterinary drugs through to the very difficult such as dioxins/furans. Suitable test materials (TM) in the appropriate matrix and containing a relevant concentration of analyte are procured and considerable effort goes into ensuring that they closely represent the samples likely to be encountered in practice. Thus, wherever possible TMs contain naturally occurring contaminants or residues rather than being spiked samples. For example animal tissue samples are obtained from treated animals and thus will contain ‘bound’ analytes closely resembling samples being routinely monitored. Demonstrating homogeneity is essential and only TMs passing rigorous homogeneity tests are used in the scheme. Although analyte stability is also important, unlike CRMs, PT materials are not tested for long-term stability and apart from decisions as to whether materials should be stored and distributed at ambient or under frozen conditions, only stability from distribution to analysis (over a few months) is sought. After PT rounds are completed, surplus TMs are sold for use as QC materials. These materials are provided together with a report indicating the assigned value for the analyte (normally the robust mean) together with the range, which would have been deemed acceptable (z-scores of + 2) in the PT round. This talk will provide some insight into the pros and cons of surplus proficiency TMs for use in food testing laboratories.
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