AOAC OMA# 2011.06 Final Action Review-OMB

2011.06 (September 2017)-Fol-22 MLT Report

FOR ERP USE ONLY DO NOT DISTRIBUTE

5. The conversion of the FA-glu3 to folic acid must be >90%, the condition of the treatment should be in line to provide the FA-glu3 to folic acid conversion of this efficiency.

I - EXTRACTION PROCEDURE Since folate compounds are light sensitive, all samples and standards must be prepared, handled, and stored in the dark or under yellow-shielded lighting or UV filtered lighting. If the standards and samples must be transported through or into an area without yellow-shielded lighting, they must be wrapped tightly in foil. A. Sample Processing All samples should be as uniform and representative of the product as possible. This should be accomplished by a thorough mixing or stirring the sample before sampling. B. Sample Preparation: All infant formula and adult nutritional powdered samples are reconstituted before the analysis. i) Weigh 25.0 g ± 0.1 g of powder into a brown glass 250 mL beaker or a bottle. Note down the weights. Cover the regular bottle/beaker with aluminum foil if brown bottles/beakers not available. ii) Add 200.0 g ± 0.1 g warm water (40 °C ± 5 °C). Mix well until complete dissolution making sure there are no lumps. Record final weight for each sample. The reconstituted samples in these cases are used for the analysis. Ready to feed samples can be used as is for the analysis after thorough mixing . C. Extraction: 1. Samples: Accurately weigh 0.2 g + (0.01) reconstituted and RTF samples in a 50 mL Centrifuge tube using analytical balance. Record weights. The sample aliquot contains 0.01 –0.5 mcg total folate. 2. Method Blank: An additional tube with no sample is added to the batch as the method blank. 3. Add 10mL of Extraction buffer containing mixed internal std (labeled folic acid, 5-CH3 –THF and 5-CHO-THF, each at 4 ng/mL). Add 50uL TCEP Solution . Vortex to mix well. 4. Add 1 mL protease solution to each centrifuge tube, fill the head space with nitrogen, cap tightly, vortex to mix and incubate for 3hrs in a shaking water bath at 37 °C (shaking speed low about 60 rpm).

Collaborative Study Report: Method AOAC 2011.06 (Folate by LC-MS/MS) 36