Amino Acids Working Group Meeting Book (July 3, 2018)

Table 3. NIST 1849a reference values for amino acids and taurine

Table 2. Method performance requirements a

Amino acid

Value, m g/100 * 0.455

Expanded uncertainty

Coverage factor

Parameter Analytical range

Minimumacceptable criteria 0.4–2500 b

Alanine Arginine

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

0.400 1.070

Limit of quantitation (LOQ)

≤0.4 b

Aspartic acid a

Cystine b

0.1286

0.0071

Recovery

0.4–5.0 b

±7% ±12% ±5% ±10% ±3% ±7% ≤6.1% ≤4% ≤4.6% ≤3% ≤3.1% ≤2% ≤8% ≤9% ≤6% ≤7% ≤4% ≤6%

Glutamic acid c

2.59

0.27

5.0–50

Glycine Histidine Isoleucine

0.241 0.315 0.660 1.261 1.010 0.516 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 0.021 0.086 0.030 0.022 0.010 0.043 0.0018

50–2500 0.4–5.0 a

Repeatability (RSD r )

5.0–50

Leucine

50–2500 0.4–5.0 b

Lysine

Reproducibility (RSD R )

Methionine

5.0–50

Phenylalanine

Proline Serine Taurine

50–2500

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.

Threonine Tryptophan

mg/100 g reconstituted final product.

b

Tyrosine

Valine

0.11

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

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

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