AOAC RI ERP EBOOK FOR FERTILIZERS

AOAC RESEARCH INSTITUTE AOAC OFFICIAL METHODS OF ANALYSIS (OMA)

«Project_Number»: «Company_Name»«Method_Name»

ER 7

Usable for a number of different ICP-OES models

Cons/Weaknesses of the Manuscript: ER 1

Address the importance of the sample prep reagents, especially for the Heavy Metals.

ER 2

None

ER 3 1. The unit in Table 9 for LOD and LOQ is incorrectly showing mg/L when it should be mg/kg. These are detection limits in the fertilizer in mg/kg after taking into account factors with digestate of 100 mL and sample wt of 1 g. They are not detection limits in the digestate which the mg/L units imply. 2. The instrument LOD and LOQ for Ni, Pb, and Se appear much too low. Are these possibly detection limits in the digestate at mg/L before calculated detection limits in the fertilizer in mg/kg? 3. A reference is presented on how LOD and LOQ were determined with a reference to (8). However, the reference list only goes up to (6). 4. Probably not necessary, but some interpretation and discussion of results for accuracy, precision, and comparability would have been nice. ER 4 Perhaps state this is intended for total metal analyses and not for water soluble. ER 5 Error in section G.(7). 400 mg/kg should be changed to 400 mg/L. 1 L acid-washed flask should be changed to 500 mL acid washed flask. ER 6 This method could not be applicable for all possible fertilizers and metals (example: selenium). ER 7 Not all of the metals are equally responsive to this method. Yes Address the importance of the sample prep reagents, especially for the Heavy Metals. Supporting Data and Information: Does data from collaborative study support the method as written? ER 1 Yes ER 2 Yes (SLV) ER 3 yes ER 4 Yes ER 5 Yes ER 6 Yes. ER 7 Yes, it appears to. Supporting Data and information: Does data collected support the criteria given in the collaborative study protocol? ER 1 Yes ER 2 Yes ER 3 yes ER 4 Yes ER 5 Yes ER 6 Yes. ER 7 Yes, it appears to. Are there any concerns regarding the safety of the method? ER 1 No ER 2 No, applicable safety information is included. ER 3 no ER 4 No

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