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Standard Interpretation

SIR #: 78
Standard: 2003 NELAC
Section: Appendix C.3.2
Link to relevant standard


The description of the LOQ does not specifiy a requirement that the standard used for verification of the LOQ include all sample processing steps (like extractions and digestions). The language presented for the LOD verification clearly states that all sample processing steps must be included in the LOD verification process. Should all sample processing steps be included in the analysis of the LOQ standard verification?


(Quality System Expert Committee/NELAP Accreditation Council, 3-x-10)

C.3.2 states 'The laboratory shall determine the LOQ for each analyte of concern according to a defined, documented procedure. This implies that the procedure used for samples and LOQ is by the same defined, documented procedure.