AOAC SPIFAN Nutrients ERP Review (March 14, 2019)

2016.13 (SEPTEMBER 2017) CAROT-02 METHOD

FOR ERP USE ONLY DO NOT DISTRIBUTE

Note on range: While this method can quantify carotenoids in the range of 1-1300 μg/100 g, it is recommended to only quantify a 100-fold difference with a single preparation. For example, the range of 1-100 μg/100 g works well for infant formula, but the range of 15- 1500 μg/100 g would work best for samples with the highest carotenoid concentrations. (a) Prepare up to 9 samples at a time. (b) Weights .—Weigh all samples (powders and liquids) to 0.1 mg. (1) Powders .—Weigh approximately 625 mg powder sample into a 50 mL centrifuge tube. Add 5 mL water, cap, and vortex until dissolved. Let sit up to 15 min at room temperature. Note : For non-homogeneous powder samples, first dissolve 25 g powder sample with 200 mL water (record weights of both powder sample and water) and then transfer approximately 5 g reconstituted sample into a 50 mL centrifuge tube. (2) Liquid ready-to-feed (RTF) with individual carotenoid concentrations ≤200 μg/100 g. —Shake bottle or can on a reciprocating shaker 10 min before opening. Transfer approximately 5 g sample into a 50 mL centrifuge tube. (3) RTF sample with individual carotenoid concentrations >200 μg/100 g .—Shake bottle or can on a reciprocating shaker 10 min before opening. Transfer approximately 2 g sample into a 50 mL centrifuge tube. Add 3 mL water, cap, and vortex 10 sec. Let sit up to 15 min at room temperature. (4) Infant formula concentrate – Shake bottle or can on a reciprocating shaker 10 min before opening. Transfer approximately 2.5 g sample into a 50 mL centrifuge tube. Add 2.5 mL water, cap, and vortex 10 sec. Let sit up to 15 min at room temperature.

(c) Pipet 5.0 mL of the appropriate ISTD solution from E(i) to each tube. (d) Add 1.5 mL KOH solution, C(l) , to each tube with a repeater pipet.