SPSFAM Heavy Metals ERP Book

Is there data demonstrating linearity, accuracy, repeatability, LOD/LOQ? If No, please explain.

Section 12.1 demonstrated LOD/LOQ

METHOD PERFORMANCE 12.1 Limits of Detection (LOD) and Limits of Quantitation (LOQ) were determined through the analysis of 23 Method Blanks. The LOD was calculated as three times the standard deviation of the results of the blanks and the LOQ was calculated as two times the value of the LOD, except where the resulting LOQ would be less than the lowest calibration point, in which case the LOQ was set at the lowest calibration point and the LOD was calculated as 1/3 of the LOQ

Section 12.2 demonstrated accuracy

12.2 Numerous relevant certified reference materials were analyzed to establish method accuracy. Example percent recoveries are provided below (recoveries have been omitted for CRMs that do not provide a certified value or if the certified value is less than the LOQ)

Section 12.4 demonstrated precision and accuracy

12.4 Matrix spikes of the Solid Milk Chocolate sample, performed in duplicate, were analyzed to establish the precision and accuracy of the method and to demonstrate the ability of the digestion procedure to overcome potential matrix- related interferences. The spiking levels, analytical results, and percent recoveries are presented below.

Repeatability was established during the ILS study just completed.

6. REPRODUCIBILITY/UNCERTAINTY AND PROBABILITY OF DETECTION

Does the available documentation demonstrate Reproducibility/Uncertainty and Probability of Detection? If yes, please specify the information provided to support the reproducibility of this method as written.

The documentation demonstrates RSD(r) and RSD(R) for the 6 QC samples. All QC samples except the Infant Formula QC material meet the requirements of the method, however, there was not enough samples.

7. FINAL ACTION REQUIREMENTS

Has the method author addressed Final Action requirements as noted by the ERP Report, if any?

Not sure.

8. RECOMMENDED CHANGES (If any)

Are there any recommended changes to the AOAC First Action method as written?

I would delete that infant formula can be run by this method. Need to redo the MLV study with more samples.