AOAC SPIFAN ERP & Working Group Method Reviews (July 10, 2019)

Table 2011.10B. Single-laboratory validation: Accuracy (spike recovery) data for vitamin B 12

No. of replicates (duplicates on multiple days)

Native level (µg/100 g RTF)

Sample type

Recovery, %

RSD, %

Infant formula (NIST SRM 1849a) Infant formula powder soy-based Infant formula powder milk-based Infant formula RTF milk-based Infant formula powder partial hydrolyzed  milk-based Infant formula powder partial hydrolyzed  soy-based Adult nutritional powder milk-based

4 6 4 6 4

42.6 a 0.404 0.236 0.326 0.347

95.7 98.2 104 96.4 98.2

5.32 5.32 4.32 8.17 6.34

6

0.248

95.7

2.51

4 6 4 4 6 4

0.298

97.4 98.6 98.2 102 105 95.1

3.86 6.76 7.98 1.61 4.45 4.38

Adult nutritional RTF high protein Child formula powder placebo Adult nutritional RTF high fat Infant elemental powder placebo Adult nutritional powder low fat

1.12

0.109

1.59 ND b

0.639

a  Results in µg/kg powder. b  ND = Not detected.

( c ) Drierite.— Desiccant, anhydrous calcium sulfate, 8 mesh. ( d ) Ethanol.— Reagent alcohol, 95%, denatured. ( e ) Formic acid.— 88%, ACS. ( f ) Laboratory water.—≥ 15 MΩ·cm . ( g ) Potassium cyanide. .—≥ 97%, ACS. ( h )  Riboflavin.—≥ 96%, ACS. ( i ) Sodium acetate anhydrous or sodium acetate trihydrate .— ACS. ( j ) Taka-diastase.— Accurate Chemical Co. (www. accuratechemical.com) or equivalent. ( k ) Triethylamine (TEA).— HPLC grade.

( l ) Vitamin B

12 (cyanocobalamin) standard.— USP reference,

official lot number (refer to USP catalog for current lot). Store in desiccator protected from white light. ( Note : See standard label for purity.) D. Solution and Standard Preparation All solutions can be scaled up or down for convenience provided good laboratory practices are observed. Solutions can be stored at 2–30°C in tight, inert containers unless otherwise noted.

Table 2011.10C. Interlaboratory study results for vitamin B 12

Total No. labs

Total No. replicates

Mean (µg/100 g RTF)

Sample type

SD

SD

RSD r

, % RSD R

, % HorRat a

r

R

Infant formula (NIST SRM 1849a) Infant formula powder soy-based Infant formula powder milk-based Infant formula RTF milk-based Infant formula powder partial  hydrolyzed milk-based Infant formula powder partial  hydrolyzed soy-based Adult nutritional powder milk-based Adult nutritional RTF high protein Adult nutritional RTF high fat Infant elemental powder Adult nutritional powder low fat Child formula powder

10 10

20 20 18 18 22

43.7 b 0.428 0.227 0.272 0.373

3.01

3.86

6.90

8.84 7.13 8.90 15.7 18.6

0.34 0.20 0.22 0.40 0.50

0.0208 0.0305 4.85 0.0111 0.0202 4.90 0.0257 0.0427 9.46 0.0200 0.0694 5.35

9 9

11

10

20

0.250

0.0244 0.0487 9.77

19.5

0.50

10 10

20 20 16 14 18 20

0.300

0.0270 0.0416 8.99

13.8 17.5 3.54 11.5 11.1 9.23

0.36 0.55 0.11 0.38 0.32 0.27

1.08

0.0730 0.190

6.74

8 9 9

0.967

0.0289 0.0342 2.98

1.48

0.122 0.171

8.23

0.543 0.636

0.0169 0.0603 3.11 0.0348 0.0587 5.47

10

a  HorRat = RSD/PRSD ∙ PRSD = 2C –0.15 (C = concentration by mass fraction). b  Results in µg/kg powder.

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