Rationale

1. Add NOTES 3.4.1.2.- after NOTE 3 the following: a. those performing the high-purity digestion would need to spike the digestion with the element of interest, and the recovery objective would need to be met for the results to be considered valid. b. Travis response on 1/15/26: Matt, From our own experience here digesting pure lead, we don’t see co-precipitation with elements at ppm levels. We do see precipitation of both Bi and Ag as noted. I would agree with the comment that the individual lab should perform some form of spike and recovery calculation to ensure their own validity. Thanks, Travis c. SECTION 17 & 18- up-date the titles to clarify the digestions. Side note: the digestions may require a updated P&B.