6. AOACSPIFANMethods-2018Awards

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8 S alvati et al .: J ournal of AOAC I nternational V ol . 99, N o . 3, 2016

Table 3. Accuracy is expressed in terms of the average over-spike recovery in select matrixes

Total B 1

Total B 2

Total B 3

Total B 6

%Rec a

Matrix

%RSD

%Rec

%RSD

%Rec

%RSD

%Rec

%RSD

Adult nutritional RTF, high-fat; placebo  Low QC 94.9

4.9 5.7

97.2 95.5

1.6 1.7

102.1 103.1

7.8 6.8

100.2

3.2 2.7

 High QC

93.4

99.5

Adult nutritional RTF, high-protein; placebo  Low QC 97.7 4.3

96.5 98.4

2.2 2.7

101.6 102.9

5.9 3.8

96.8 98.8

2.4 2.7

 High QC

95.4

5.5

Child formula powder, placebo  Low QC 99.0

5.7 7.0

98.0 98.9

2.7 2.8

105.4 105.7

6.3 5.3

99.7 99.1

1.8 1.9

 High QC

97.0

Infant elemental powder, placebo  Low QC 93.7

6.4 7.8

95.1 96.7

1.8 1.0

104.5 103.8

6.8 4.9

97.9 98.4

2.1 3.4

 High QC

92.4

Infant formula powder partially hydrolyzed, milk-based  Low QC 100.5 1.9

100.2 100.0

1.6 2.4

103.8 111.7

1.2 1.7

99.1

1.5 2.9

 High QC

101.3

1.8

100.1

Infant formula powder partially hydrolyzed, soy-based  Low QC 100.7 1.5

100.7

2.1 2.0

102.0 106.7

0.9 1.1

99.3 99.8

0.9 2.4

 High QC

103.1

0.6

99.6

Infant formula powder, soy-based  Low QC 99.3

1.4 3.4

95.7 96.8

4.4 2.9

101.1 100.1

1.7 2.9

98.9 97.2

1.3 2.0

 High QC

96.6

Infant formula RTF, milk-based; placebo  Low QC 96.9

4.3 6.1

100.7

1.8 3.2

105.3 103.3

5.7 6.9

98.6 99.6

2.8 3.8

 High QC

95.5

97.9

A cocktail including all vitamin forms listed in the SMPRs was spiked at approximately 50 and 200% of the fortification level. a  %Rec = Percent recovery.

Despite the degree of signal suppression, ion ratio stability between the two transitions was demonstrated to be good across matrixes. For vitamin forms with modest signal intensity (pyridoxine, thiamine, nicotinamide, and riboflavin), ion ratios in the samples averaged 101 ± 3% of the ion ratio in the standards.

standards for good method precision and accuracy. Standard addition is an alternative means to quantitate without stable- isotope labeled internal standards, but was not evaluated in this method because it is not practical when many different matrix types are tested within a single run.

Table 4. Repeatability for six independent preparations is expressed as %RSD Matrix Total B 1 Total B 2

Total B 3

Total B 6

S01: 1849a

1.0 0.7 0.8 1.2 1.1 1.8 1.6 0.6 1.1 1.0 0.9 0.9 1.8 1.0

1.8 1.7 2.3 2.8 2.3 3.8 2.6 2.6 2.6 2.3 1.4 1.6 2.4 1.6

1.2 1.6 1.2 1.0 1.3 1.7 1.3 0.6 1.0 1.0 1.0 0.9 1.9 1.0

1.0 1.5 1.3 4.2 1.1 1.5 0.8 1.6 0.8 1.1 1.2 1.0 2.9 1.5

S02: Infant formula powder partially hydrolyzed, milk-based S03: Infant formula powder partially hydrolyzed, soy-based

S04: Toddler formula powder, milk-based S05: Infant formula powder, milk-based S06: Adult nutritional powder, low-fat

S07: Child formula powder S08: Infant elemental powder

S09: Infant formula powder FOS/GOS-based a S10: Infant formula powder, milk-based S11: Infant formula powder, soy-based S12: Infant formula RTF, milk-based S13: Adult nutritional RTF, high-protein S14: Adult nutritional RTF, high-fat

a  FOS/GOS = Fructo-oligosaccharides/galacto-oligosaccharides.