AOAC SPIFAN Nutrients ERP Review (March 14, 2019)

2016.13 (Jan. 2019) Carot-02 MLT Report FOR ERP USE ONLY DO NOT DISTRIBUTE

internal standard by plotting peak area ratios against concentration ratios, with relative concentration on the x-axis. The accuracy on calibration points should be 100% ± 10% for calibration solutions C1- C4, and the coefficient of determination (R 2 ) should be greater than 0.995. The calibration and calculation may be achieved through data processing within the instrument software or off-line. (i) Calculate the mass of apocarotenal (M A ), in μg, added to the test samples: M A = (C A /100) × V A × (4/50) where C A = the concentration of apocarotenal in the intermediate or WS used in the ISTD solution (μg/100 mL); 100 = conversion from μg/100 mL to μg/mL; V A = the volume of ISTD solution added to each sample, in mL; 4 = the volume of apocarotenal intermediate or WS used in the ISTD solution, in mL; 50 = the total volume of ISTD solution made, in mL. (j) Calculate the contents of all- trans lutein, cis isomers of lutein, and total lutein on an as-is basis in the test samples. For peak identification, refer to relative retention times of peaks in Figures A , C , and D . Lut trans = (M A /M S ) × ([A Lut /A A ] – I Lut ) × (100/RF Lut ) where Lut trans = the all- trans lutein in the sample (μg/100 g); M A = the mass of apocarotenal added to the test sample, in μg; M S = the sample weight, in g; A Lut = the peak area of all- trans -lutein in the sample chromatogram, in arbitrary units; A A = the peak area of apocarotenal in the sample chromatogram, in arbitrary units; I Lut = the y- intercept of the calibration curve for all- trans -lutein; RF Lut = the slope of the calibration curve for all- trans -lutein.

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