AOAC SPIFAN Nutrients ERP-Final Review (Oct. 2018) Pubs

2011.06 (September 2017)-Fol-22 MLT Report

FOR ERP USE ONLY DO NOT DISTRIBUTE

The value of folate vitamer concentration (ng/mL) so calculated are in the same form of salt in which folate compound used to make the calibration standard. Methyl-THF as well as formyl-THF used are in the form of calcium salt. The Calculation template then calculates salt free concentration of the folates from values of calcium salt of methyl-THF and formyl-THF. So adjusted values of folates for salt free form in the sample extract is multiplied by dilution volumes (if any) and final volumes of the elute (= 1.05 mL) to calculate total amount of folate vitamer in the extract. The value is then divided by sample aliquot used for the analysis to calculate values of folate vitamers (mcg/g) in the reconstituted or RTF sample. Folates other than folic acid in the samples (mcg/100g) are calculated as folic acid by multiplying (mcg/g) concentration of the folate compound by the following conversion factors. Total folate in the sample is calculated by sum of all folate compound as folic acid (mcg/g) and multiply by 100 to report total folate as folic acid (mcg/100g) in reconstituted or RTF samples.

Multiply by to convert to FA

Example value mcg/100g

Formula Weight

Value as FA mcg/100g

Folate Vitamers

441.4

1

100.0

100.0

Folic Acid

5-CH3-THF

459.5

0.9606

100.0

96.1

5-CHO-THF

473.4

0.9324

100.0

93.2

Total Folate as FA

Sum as FA

289.3

Calculation of total folate in samples (mcg/100g) in samples (as is basis): This calculation is done automatically by the Calculation Template (Appendix D). This calculation in the Calculation Template is performed (in Tab “AS is basis”) by using values it calculated for corresponding samples for total folate (mcg/100g) in reconstituted or RTF samples. The calculation of total folate (mcg/100g) as is basis from total folate (mcg/100) in reconstituted beverage samples is calculated based on the following relationship. Total Folate as is basis (mcg/100g) in samples analyzed as reconstituted beverage = C (mcg/100g) * V (g)/W (g) C (mcg/100g) = Total folate in reconstitituted samples

Collaborative Study Report: Method AOAC 2011.06 (Folate by LC-MS/MS) 45