MCPD-02 Reviewer Forms (July 19, 2018)

FOR EXPERT REVIEW PANEL USE ONLY NOT FOR DISTRIBUTION

Reviewer 1

• Use of GC single quad; quantitation of free and bound analytes in powders does not require separate extraction procedures • Additional text describes modification of samples (either lyophilization of liquid samples or preparation of powdered samples with water) so that a single extraction procedure can be used for all formula samples

Cons/Weaknesses

• Likely requires high level of technical expertise

Supporting Data

• General Comment:

• Note in Section C indicates the purity of the labeled internal standards can be assessed by comparison of the internal standard response to its corresponding native analyte response (response factor of 1) - Method Optimization: • Performance Characteristics: Analytical Range: • Included note that SLV and other validation studies using GC-MS systems have shown that the response factors for the target ions listed in the method (for labeled internal standards and corresponding analytes) are close to 1; linearity of data in SLV report supports response factors are concentration independent • Note in Section B indicates response factor testing should be repeated when using a different GC-MS system. (Note also discusses isotopic purity verification) • Quantitation based on one-point internal standard calibration; SLV validation shows acceptable linearity and precision with single point calibration – additional text in Section A indicates external calibration can be used. • Suitable for range specified in SMPR; may also be applied to more concentrated samples by dilution with a suitable blank material • Meets requirements of SMPR • Defined as s/n ≥ 10; free analytes in powder: 5 µg/kg, free analytes in liquid: 1 µg/kg, bound analytes in powder: 10 µg/kg, bound analytes in liquid: 2 µg/kg Accuracy/Recovery: • Formula reference material unavailable – FAPAS QC sample (soy sauce) • Spiked/native recoveries and dilutions of mixed samples: 90-113% Precision (RSD r ): • Determined in powder and liquid formulas • RSDr: 1.2-12% (across bound and free analytes in liquid and powder formulas) LOQ:

Reproducibility (RSD R ):

2