TNI Logo The NELAC Institute

Standard Interpretation

Standard: 2003 NELAC
Section: Appendix D.1.2.1 (b)


In reviewing an onsite report for metals analyses, the auditor noted that the lab did perform LOD analyses annually but that the LODs for vanadium and arsenic were lower than the blank analysis and that new LODs and LOQs must be reestablished. I see nothing in D1.2.1.b that makes any comparison of an LOD to the blank results. Does an LOD need to be higher than the blank?


(Quality Systems Expert Committee and NELAP AC, 10-7-13)

There is no requirement to compare the LOD with the blank. Theoretically, a blank should have no detectable contaminants. Any detection in a blank must be evaluated according to D.1.1.1d).