AOAC Final Action Methods in 2017

840 J OSEPH ET AL . : J OURNAL OF AOAC I NTERNATIONAL V OL . 101, N O . 3, 2018

Table 6. Biotin (µg/100 g) MLT samples (day 2)

Biotin concentration, µg/100 g

MLT sample 7

MLT sample 8

MLT sample 9

MLT sample 10

MLT sample 11

MLT sample 12

Lab No.

A

B

A

B

A

B

A

B

A

B

A

B

1 2 3 4 5 6 7 8 9

195.27 200.37 270.20 265.83 171.08 155.73 10.69

9.80

44.26 44.68 48.66 56.39

200.63 191.30 271.16 266.46 180.38 159.53 11.11 10.68 46.01 43.08 52.02 53.47 196.99 196.48 265.19 272.41 179.63 168.93 10.40 10.24 42.19 43.96 54.56 54.37

191.31 205.32 251.11 265.49 171.89 162.31 11.19 196.80 196.60 260.67 247.84 170.46 161.75 193.53 186.75 263.54 248.41 184.86 161.43 185.41 190.38 219.30 213.21 153.16 140.19 10.05 9.76 9.88

9.20 9.37 9.89 9.15 9.59

44.02 44.66 54.54 54.92 40.82 40.13 52.48 49.79 43.31 42.48 53.84 56.11 38.43 39.03 50.09 50.14 40.44 42.14 52.00 44.45

Downloaded from https://academic.oup.com/jaoac/article-abstract/101/3/831/5653969 by guest on 05 May 2020

201.99 199.82 268.69 254.35 175.94 163.60

9.36

202.58 205.62 278.04 274.41 183.98 158.33 11.02 10.72 46.05 46.44 55.47 54.89

Mean

196.06 196.96 260.88 256.49 174.60 159.09 10.38

9.85 6.02

42.84 42.96 52.63 52.73

RSD, % 2.81

3.33

6.64

7.37

5.55

5.02

6.35

6.05

5.42

4.24

7.39

Recommendations

Filtrate for IAC Cleanup

One of the participants commented that the filtrate for IAC cleanup was not clear and suggested that the same extraction procedure would also be efficient if performed at pH 4, which would precipitate many of the proteins, yielding a clear filtrate. My laboratory tested a few SPIFAN matrixes using sodium acetate solution 0.4 M, pH 4.0 (weigh 108.8 g sodium acetate trihydrate into a 2000 mL volumetric flask, add about 1800 mL water, and dissolve; add 50 mL acetic acid and adjust pH to 4.0 with acetic acid; dilute to volume with water). The filtrate was clear, IAC cleanup was faster, and the biotin results were comparable to the current method. However, this change was not advised to any of the collaborators, and the participant was advised to proceed with the current method as published as First Action Official Method 2016.02 .

A complete AOAC MLT study workbook and the statistical report and draft copy of the study report summarizing the outcomes of this collaborative study were submitted with the recommendation that AOAC First Action Official Method SM 2016.02 be accepted as a SPIFAN-endorsed AOAC Final Action Official Method .

Notes from the Study Director

I would like to place on record what I learned and experienced in working with the collaborators during the course of the study. I believe that noting feedback, challenges, and ideas for improvement are valuable information for any future enhancement to the method.

Table 7. Statistical evaluation biotin results from SPIFAN matrixes

P a

r , % RSD R , % HorRat b

Sample

Product description

Mean

RSD

Practice 1 Practice 2

Infant formula powder, partially hydrolyzed soy-based

12 12

38.59 14.94 34.01 79.20 71.46 26.97 44.75 196.5 258.7 166.8 10.12 42.90 52.68 4.07

3.18 4.92 5.53 2.64 5.52 3.88 6.79 5.77 2.38 2.81 7.03 5.74 2.26 5.14

6.98 7.74 9.48 5.14 7.59 7.75 8.76 6.96 3.04 7.03 7.03 6.65 5.72 5.89

0.38 0.36 0.50 0.31 0.29 0.46 0.45 0.39 0.21 0.51 0.47 0.29 0.31 0.33

Infant formula powder, FOS/GOS-based c

MLT-1 MLT-2 MLT-3 MLT-4 MLT-5 MLT-6 MLT-7 MLT-8 MLT-9 MLT-10 MLT-11 MLT-12

Infant formula powder, partially hydrolyzed milk-based

9 9 9 9 9 9 9 9 9 9 9 9

Infant elemental powder

Infant formula RTF, milk-based d

Adult nutritional RTF, high-fat

Infant formula powder, milk-based Infant formula powder, soy-based

NIST SRM 1849a

Adult nutritional powder, low-fat

Child formula powder

Toddler formula powder, milk-based Infant formula powder, milk-based

Adult nutritional RTF, high-protein

a

P = Number of laboratories.

b

RSD

R /PRSD R .

c FOS/GOS = Fructooligosaccharide/galactooligosaccharide. d RTF = Ready-to-feed.