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Standard Interpretation

Standard: 2009 TNI
Section: V1M4, Section 1.6.2 and 1.6.3


Are the DOC requirements in V1M4 sections 1.6.2 and 1.6.3 specific to each Matrix-Method-Analyte combination for which a laboratory seeks or maintains accreditation? The language implies that they are, and because laboratories are accredited by Matrix-Method-Analyte, should be, but it is not explicit enough to preclude another interpretation.


Section 1.6.2 (IDOC) is specific to each matrix-method-analyte combination.

Section 1.6.3 (ODOC) does not state that it is specific to each matrix-method-analyte combination. The standard allows the use of an LCS or PT samples which are not required to contain every compound according to the standard as acceptable forms of ODOC.

The standard does not require ongoing DOC to be matrix-method-analyte combination specific however we have expanded and clarified the response to the best of our ability and do intend to revise the DOC section of the standard in the next revision. The input from the ABs has already been requested and received on this and continued input will be sought so that the standard can be modified to a procedure that is believed to be adequate by the ABs in the next revision.

Individual NELAP ABs may have more stringent requirements. V1M4 Section 1.2 states that additional QC requirements that are either specified by method, regulation or project shall be met by laboratories.