Carn-06_Book_Final

Carn-06 Comments FOR ERP USE ONLY DO NOT DISTRIBUTE

AOAC INTERNATIONAL Eurofins (Carn-06 Comments Received)

Carn-06

Additional Recommendation(s)

Comments: 1. The authors need to provide data of the method performance (accuracy and inter-day precision) on analysis of the SPIFAN samples.

2. Data for spike recovery at different concentration of the analytical range may be generated using SMPR matrices to make sure the method performs with in the SMPR requirements in this respect.

3. Recovery of carnitine from Acetyl carnitine by the method may be evaluated to establish a satisfactory analysis of the method of the bound carnitine also.

4. A satisfactory recovery and the method performance at the LOQ level (0.2 mg/100g) may be established.

I recommend this method with additional documentation

5. The authors may confirm the specificity of the carnitine analysis by the method in the SPIFAN matrices by use of a confirmation transition. The authors may confirm that the identity of carnitine in the analyzed matrices was established by use of the “confirmation transition”.

6. SRM 1849a carnitine value is based on the free carnitine analysis and may not establish accuracy of the total carnitine analysis by the method.

7. The method has not been applied to any infant formula and adult nutritional matrices. The method performance on these matrices should be with in the SMPR requirements for further consideration of the method.

8. The method accuracy need to be established by analysis of a sample within the SMPR scope whose total carnitine value is known by reference analysis or some other way.

1.) Reproducibility data was collected on a "milk powder" sample, but in the text it says this was an infant formula sample. Can the authors provide clarification on the identity of this sample?

I recommend this method with additional documentation

2.) Can the authors provide their reference(s) for the free choline and total carnitine reference values cited for SRM 1849A ? They are not included in the certificate from NIST.

I do not recommend this method

I do not see enough performance data to indicate that this method is "fit for purpose"

Method 05 already has data on the SPIFAN matrices where this method only has data on the NIST. Without the data on the SPIFAN matrices, one can not tell if the method would work on the various products within the SPIFAN kits. Personally, I would like to see Choline and Carnitine results for both methods submitted on the SPIFAN kits before moving either method forward.

I recommend this method with additional documentation