develop consensus standards for use by TNI's programs. This group has a support role in assisting other programs with activities such as guidance and standards interpretation.
fosters the generation of data of known and documented quality is through the National Environmental Laboratory Accreditation Program, or NELAP. The purpose of this program is to establish and implement a program for the accreditation of environmental laboratories.
is to establish and maintain a national PT program to support TNI’s National Environmental Laboratory Accreditation Program, and other activities.
Field Activities Program (NEFAP) Executive Committee is to establish and implement an accreditation program for field sampling and measurement organizations (FSMOs).
on a variety of topics of interest to the environmental measurement community. TNI also hosts two regularly scheduled meetings per year, typically in January and August. Both are a week long and involve open meetings of TNI committees as well as training courses and other special sessions.Standard Interpretation
Standard: 2003 NELAC
Section: Appendix C.3.2 (c)
Link to relevant standard
REQUEST:
Is it acceptable to demonstrate the accuracy and precision at the Limit of Quantitation (LOQ) using a concentration that is less than the LOQ, including down to 1/2 the LOQ?
TNI FINAL RESPONSE:
(Quality System Expert Committee/NELAP Accreditation Council, 2-10-13)
NELAC C.3.2.c)
"The validity of the LOQ shall be confirmed by successful analysis of a QC sample containing the analytes of concern in each quality system matrix 1-2 times the claimed LOQ."
The standard requires concentrations that are 1-2 times the claimed LOQ. A concentration below the LOQ may not have the same accuracy and precision and therefore could not be used to verify the LOQ.