TNI Logo The NELAC Institute

Standard Interpretation

Standard: 2003 NELAC
Section: Appendix D. (c)
Link to relevant standard


With regards to the requirement of spiking all targeted components over a 2-year period, is this an overall requirement per ANALYTE or per METHOD? As an example, we analyze pesticides by EPA 525.2 and EPA 8270C. Can we spike all target analytes for one method and cover the other? Or must we spike all for both methods?


(Quality System Expert Committee/NELAP Accreditation Council, 9-18-12)
The standard for multi-analytes tests requires that all targeted components be included in a spike mixture for evaluation during a 2-year period and includes any reported analyte (whether detected or not).The committee noted that the preparation for 525.2 and 8270C are different, and spike results could differ. Therefore, each method requires a separate spiking schedule. Methods 624 and 8260, which use the same preparation procedure, could use the same spiking study.