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

pediatric, and adult nutritionals. Repeatability was determined from duplicate analyses performed on multiple days. Accuracy was determined from spike recovery experiments (free myo-inositol and myo-inositol from phosphatidylinositol). Instrument limits of detection and quantitation were determined statistically from injections of low-level standards and by spiking samples with low levels of free myo-inositol. See Tables 2011.18A – C for method performance information supporting acceptance of the method. Caution: Refer toMaterial SafetyData Sheets (MSDS) of chemicals prior to use and follow safe handling procedures and the suggested personal protective equipment. Chloroform is a hazardous chemical and should be handled in a fume hood. Perform the phosphatidylinositol bound myo- inositol extraction and SPE sample cleanup procedure in a fume hood. A. Apparatus ( a ) Analytical balance .—Minimum weighing capacity of at least 0.0001 g.

AOAC Official Method 2011.18 Myo-Inositol (Free and Bound as Phosphatidylinositol) in Infant and Pediatric Formula and Adult Nutritionals Liquid Chromatography/Pulsed Amperometry with Column Switching

First Action 2011 Final Action 2014

ISO–AOAC Method* The liquid chromatography method with electrochemical (pulsed amperometry) detection (PAD) allows for the quantitation of myo- inositol in infant, pediatric, and adult nutritional formulas. The concentration of myo-inositol is calculated by comparison with standards of known concentration. Myo-inositol, as defined by AOAC SMPR 2011.007 (free and bound as phosphatidylinositol), can be calculated by adding the free myo-inositol and myo-inositol bound as phosphatidylinositol data. The method was validated for the quantitation of free myo- inositol and myo-inositol from phosphatidylinositol in infant,

Table 2011.18A. Single-laboratory validation: Repeatability precision data for myo-inositol

No. of replicates (duplicates on multiple days) Unbound (free) myo-inositol

Mean (mg/100 g RTF)

Sample type

SD

RSD r

r

Infant formula (NIST SRM 1849a) Infant formula powder soy-based Infant formula powder milk-based Infant formula RTF milk-based

14 14 14 14 14 14 14 14 14 12 12 12 12 12 12 12 12 12 12 12 12 12 12

415 a 4.19 4.21 7.19 3.38 3.10 4.85 5.04 3.17 1.74 1.94 61.4

8.30

2.00 2.17 2.32 3.48 2.95 2.02 3.06 2.22 1.47 1.89 2.46 3.05 5.05 2.40 4.00 3.36 4.43 4.69 1.96 1.63 2.76 1.80 2.07

0.091

0.0977

0.250

Infant formula powder partial hydrolyzed milk-based Infant formula powder partial hydrolyzed soy-based

0.0997 0.0626

Infant elemental powder Child formula powder

0.148 0.112

Infant formula RTF milk-based, unfortified Infant elemental powder, unfortified

0.0466 0.0329 0.0477

Child formula powder, spiked

Adult nutritional RTF high protein, spiked

1.87

Myo-inositol bound as phosphatidylinositol

Infant formula (NIST SRM 1849a) Infant formula powder soy-based

10.6 a 2.48 0.244

0.536

0.0595 0.00976 0.0664 0.0196

Infant formula powder partial hydrolyzed milk-based Infant formula powder partial hydrolyzed soy-based

1.98

Child formula powder

0.443

Adult nutritional powder, milk protein-based

1.43

0.067

Unbound (free) myo-inositol plus myo-inositol bound as phosphatidylinositol

Infant formula (NIST SRM 1849a) Infant formula powder soy-based

426a 6.67 3.63 5.08 5.48

8.35

0.109 0.100

Infant formula powder partial hydrolyzed milk-based Infant formula powder partial hydrolyzed soy-based

0.0914

Child formula powder a  Results in mg/kg powder.

0.113

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