AOAC RI ERP EBOOK FOR FERTILIZERS

Author Response to Reviewers 071506_OMAMAN-28-AOAC 2006.03_rev 071816

Author Response to Reviewers: 1. Table 6, which is the comparison of the results of certified and consensus values for all elements included in this study, has been updated to include a bias for both the NIST-SRM 695 and Magruder 2009-06. Please see the attachment for corrections. 2. Table 7, which is demonstrates the method precision and comparability to the 2006.03 method using some of the original materials and original included elements, has been updated using the statistician’s suggestion of multiplying the found Horrat value by two. Please see the attachment for corrections. Please see the attachment for corrections. 3. Table 8, which is the method precision for the proposed included elements (Ca, Cu, Fe, Mg, and Mn) using some of the original study materials, has been updated using the suggestion from the statistician of multiplying the found Horrat value by two. Please see the attachment for corrections. 4. The author recommends a change to the 2006.03 method for the removal from the scope of arsenic, selenium, and lead due to poor statistics. However, at the time of the publication, it was the best method available using common equipment found in both state regulatory and commercial laboratories. The improvement of the added hydrochloric acid to the method will provide adequate recovery, reproducibility, and trueness of the results lacking in the nitric only method. 5. Spike method: This method will be changed to a new method and it is not addressed at this time. 6. Please see the attachment labeled: “Fertilizer Subgroup Metals Statement Rev_071516_OMAMAN-28-AOAC 2006.03” for further explanations regarding this method.