AOAC SPIFAN Review Team Meeting Book-July 22, 2015

BVIT-02 FOR ERP/WORKING GROUP USE ONLY DO NOT DISTRIBUTE

Abbott Nutrition Division Simultaneous Determination of Total Vitamin B 6, B 2, B 3 in Infant Formula Products by LC-MS/MS Using Enzymatic Digestion and B 1

Table 6. Example Pyridoxine Standard Curve. Standard [PN] ng/mL

Response Ratio

WS1 WS2 WS3 WS4 WS5 WS6

3.195 7.984 15.976 31.952 79.84 159.76

0.312 0.779 1.592 2.931 7.48 18.113

Slope = 0.1123 y-intercept = -0.3894 Coefficient of Determination (r 2 ) = 0.9961

7. Liquid and Powder Product Calculation MassLynx is used to calculate both the vitamin concentration in the analytical sample and in the original sample. The following equation is used for this calculation

FSW ASW RW Vit

AS ] [

× × ×

Vit

] [

=

sample

PW

where:

[Vit] sample

: Vitamin concentration in Product Sample, m g/kg

[Vit] AS : Vitamin concentration in the Analytical Sample; ng/g RW: Reconstitution Weight (total), g. For direct weight (liquid) samples RW=1 ASW: Analytical Sample Weight, g -1 . Due to limitations in MassLynx, the sample weight must be entered as the inverse, i.e. for a 0.5 sample, SW=2.0 FSW: Final Sample Weight, g. As each compound has an internal standard added to the sample this value is set to 25.0g for every sample PW: Powder Weight (for reconstituted samples), g. For direct weight samples, this value is 1 Example: 10.04 g of Similac Pwd. is reconstituted into laboratory water (PW) resulting in a final recon weight (RW) of 102.386 g. 1.0298 g of slurry (ASW) is weighed into a tarred centrifuge tube and prepared per method with a final sample weight (FSW) of 25.0. The Pyridoxine concentration in the analytical sample ([Vit] sample ) is determined to be 8.6318 ng/g. The Pyridoxine concentration in the original Similac pwd. sample is calculated as follows:

1

−

g ng ×

g 9711 .0 386 . 102 / ×

g

g 0.25

6318 .8

×

g ng 2143 / 4. =

kg g / 4.

PN

2143

sample ] [

=

=

m

g

04.10

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