AOAC SPIFAN ERP Reviewer Forms (March 16, 2017)

FOR EXPERT REVIEW PANEL USE ONLY NOT FOR DISTRIBUTION

General safety section needs to be added to the method

Pros/Strengths: • Well laid out method with good detail. • ISTD added at beginning of sample preparation • Instrument and reagents (other than enzyme) are commonly used in the lab • No hush sample treatment is involved. Cons • Enzyme effectiveness will be critical for the assay. Need to mention how to ensure the effectiveness of the enzyme and how it is controlled. • More specific information required for sample weight to be used. • System suitability: As per SMPR, System Suitability Tests and/or Analytical Quality Control should be included in the method. An enzyme blank is included but others required, for example, standard repeatability, slope accuracy, linearity > 0.995

Supporting Data • General Comment:

- Method Optimization: Optimized with enzyme blank subtraction

Method performance requirements:

SMPR: Applicability: Determination of free and/or total proteinogenic L-α-amino acids and taurine (as shown in Table 1) in all forms of infant, adult, and/or pediatric formulas (powders, ready-to-feed liquids, and liquid concentrates).

Analytical range

0.4–2500 mcg/100g RTF

Limit of quantitation (LOQ)

≤ 0.4 mcg/100g RTF

Recovery

90–110% 0.4–5.0 5.0 – 50 50 – 2500 0.4–5.0 5.0 – 50 50 – 2500

Repeatability (RSDr)

≤ 4% ≤ 3% ≤ 2 % ≤ 6% ≤ 4% ≤ 3 %

Reproducibility (RSDR)

Linearity: Minimum of six levels (levels to be agreed upon by SDs) that span the desired working range. (b) Relative error of back-calculated concentrations determined within the desired working range. (No specifi c criterion in standard method performance requirement. Recommend calibration errors to be <5%.) (c) Minimum of three independent experiments. (Independently prepared standards, if feasible.)

Analytical Range: 0.18-300mg/100g of RTF sample (including reconstitute sample)

Linearity: 0.2 – 30 mg/L tryptophan. 8 levels in triplicate with max 1.35 % calibration error

LOQ: 0.18 mg/100g. 0.007 mg/L * 10 = 0.07 mg/L

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