AOAC SPIFAN Nutrients ERP Review (March 14, 2019)

2016.13 (SEPTEMBER 2017) CAROT-02 METHOD

FOR ERP USE ONLY DO NOT DISTRIBUTE

C Lut = W Lut × 2 × (P Lut /100) × 1000 × (2/100) × (V MC /V Total ) where W Lut = the weight of lutein used to make the stock solution, in mg; 2 = conversion of 50 mL to 100 mL; P Lut = the reference standard purity of all- trans -lutein calculated in H(a)(3) above; 100 = conversion from percent to decimal; 1000 = conversion of mg to μg; (2/100) = the dilution of stock solution to mixed carotenoid intermediate solution; V MC = the volume of mixed carotenoid intermediate solution, E(e) , used; V Total = dilution volume (c) Calculate the concentration of the apocarotenal internal standard (C A ), in μg/100 mL, in each calibration solution, E(f) : C A = W A × 2 × CP A × 1000 × (3/50) × (V AI /V Total ) where W A = the weight of apocarotenal used to make the stock solution, in mg; 2 = conversion of 50 mL to 100 mL; CP A = the chromatographic purity of apocarotenal calculated in H(a)(2) above; 1000 = the conversion of mg to μg; (3/50) = the dilution of stock solution to apocarotenal intermediate solution; V AI = the volume of apocarotenal intermediate solution, E(d) , used; V Total = dilution volume. (d) For each calibration solution calculate ( 1 ) the peak area ratio for each analyte (peak area [all-trans lutein, β -carotene, or lycopene])/(peak area [internal standard]) and ( 2 ) the concentration ratio (concentration [all-trans lutein, β -carotene, or lycopene])/(concentration [internal standard]). Build a 5-point calibration curve with 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 solution C1-C4, and the coefficient of determination (R 2 ) should be greater than 0.995.