Article taken from (and can be viewed at) the following NELAC website:
http://www.epa.gov/nerlesd1/land-sci/nelac/accrauth/aapt_final110304.pdf
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Complete article from Edition 25 APG eNewsletter
NELAP Accrediting Authorities’ (AA) Policy and Implementation of Section 2.5 of the NELAC 2003 Standard Policy Revision 1 Performance Testing (PT) Samples must be Analyzed as Routine Samples. (Approved by AA s 11-3-04) Section 2.5 of the NELAC standard states the following:
"The samples shall be analyzed and the results returned to the PT Provider no later than 45 calendar days from the opening of the study (i.e. first day that samples are shipped or available to laboratories). The laboratory’s management and all analysts shall ensure that all PT samples are handled (i.e., managed, analyzed, and reported) in the same manner as real environmental samples utilizing the same staff, methods as used for routine analysis of that analyte, procedures, equipment, facilities, and frequency of analysis.
When analyzing a PT sample, a laboratory shall employ the same calibration, laboratory quality control and acceptance criteria, sequence of analytical steps, number of replicates and other procedures as used when analyzing routine samples".
NELAP Accrediting Authorities (AA) shall assess the laboratory’s compliance with the requirements of this section of the standards during data review and on-site assessments. The laboratories shall be penalized for violations in accordance with the NELAC standards and the AA’s due process rules.
The AAs at a minimum will check for the following:
1. PT samples are entered into the laboratory sample receipt log as samples and are tracked through the laboratory as routine environmental samples. The laboratory records used to track PT samples (e.g., chain-of-custody) can be initiated by laboratory personnel such as the Quality Assurance Officer.
2. PT samples received as ampules are diluted according to the PT provider’s instructions. The diluted PT sample becomes the routine environmental sample. The sample is added to a routine sample batch.
3. Sample Preparation for PT samples (e.g., digestion or extraction) is the same as for routine environmental samples.
4. Instructions shall be included in the laboratory’s standard operating procedure (SOP) for how low level samples will be analyzed, including concentration of the sample or adjustment of the normality of a titrant. Theses instruction shall be followed when the concentration of a PT sample falls below the range of their routine analytical method. Instructions shall be included in the laboratory’s SOP for how high level samples will be analyzed, including preparation of multiple dilutions of the sample. These instructions shall be followed when the concentration of a PT sample falls above the range of their routine analytical method.
5. PT samples that consist of a set of individual samples (e.g., microbiology PTs) shall be analyzed according to the laboratory’s routine procedures.
6. PT samples shall not be analyzed multiple times unless routine environmental samples are analyzed multiple times. Results from multiple analyses must be calculated in the same manner as routine environmental samples.
7. The type, composition, concentration, and frequency of quality control samples analyzed with the PT samples shall be the same as with routine environmental samples.
8. Initial and continuing calibrations shall be at the same frequency as with routine environmental samples.
9. The AA must make a documented determination when exceptions to any of these requirements are applicable on the basis of the laboratory’s routine environmental sample composition and SOPs.
Any AA that finds a PT Provider directing or suggesting that laboratories use additional QC, offering QC samples that are specifically designed for a given PT, or providing instructions beyond sample preservation and preparation of Pt samples from ampules, shall report the actions to the NELAC PT Board with documentation.
This policy shall be implemented by the AAs with in 30 calendar days of posting on the NELAC web site.
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