AOAC Working Group Chair Orientation

Table 3. NIST 1849a reference values for amino acids and taurine Amino acid Value, mg/100 g a Expanded uncertainty Coverage factor

Table 2. Method performance requirements a Parameter

Minimum acceptable criteria

Analytical range

0.5–2500 b

Limit of quantitation (LOQ)

≤0.5 b

Alanine Arginine

0.455 0.400 1.070

0.021 0.029 0.057

2.31 2.31 2.31 2.00 2.31 2.31 2.31 2.31 2.31 2.31 2.31 2.31 2.31 2.00 2.31 2.45 2.31 2.31

Recovery

0.5–5.0 b 5.0–150

±12% +10%

Aspartic acid b

150–2500

+7% ≤7% ≤5% ≤3%

Cystine c

0.1286

0.0071

Repeatability (RSD r )

0.5–5.0 b 5.0–150

Glutamic acid d

2.59

0.27

Glycine Histidine Isoleucine

0.241 0.315 0.660 1.261 1.010 0.482 0.580 1.195 0.720 0.640 0.184 0.510 0.0366 0.7600

0.019 0.036 0.071 0.050 0.071 0.051 0.021 0.086 0.030 0.022 0.010 0.043 0.0018

150–2500

Reproducibility (RSD R )

0.5–5.0 b 5.0–150

≤11%

≤8%

Leucine

5 System Suitability Tests and/or Analytical Quality Control Suitable methods will include blank check samples, and check standards at the lowest point and midrange point of the analytical range. 6 Reference Material(s) NIST Standard Reference Material® 1849a Infant/Adult Nutritional Formula, or equivalent. SRM 1849a is a milk-based, hybrid infant/adult nutritional powder. One unit of SRM 1849a contains 10 packets each containing approximately 10 g of material. The SRM 1849a certificate values for amino acids and taurine are reference values and are for total content (Table 3). Other reference materials may be specified. 7 Validation Guidance Recommended level of validation: Official Methods of Analysis SM . 8 Maximum Time-to-Result No maximum time. Approved by Stakeholder Panel on Infant Formula and Adult Nutritionals (SPIFAN). Final Version Date: September 6, 2014. Effective Date: November 13, 2014. Revised: August 25, 2018. ≤5% a  Concentrations apply to: ( a ) ‘ready-to-feed” liquids “as is”; ( b ) reconstituted powders (25 g into 200 g water); and ( c ) liquid concentrates diluted 1:1 by weight using water. b  mg/100 g reconstituted final product. 150–2500

Lysine

Methionine

Phenylalanine

Proline Serine Taurine

Threonine Tryptophan

Tyrosine

Valine

0.11

a  As-is basis. b  Sum of Asp+Asn. c  Sum of CSSC and Cys. d  Sum of Glu+Gln.

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