A rapid, high-performance liquid chromatographic (HPLC) method for the determination of vitamins A and D in fortified skimmed milk powder (SMP) is described. Either vitamin D2 or D3 is added as an internal standard, depending upon which formulation has been used for fortification, and the sample is saponified and extracted. Vitamin A can be determined directly (without further clean-up) in a portion of this extract using reversed-phase HPLC. Vitamin D is determined on the remainder of the extract after clean-up using a Sep-pak cartridge and the same HPLC system. Details of recoveries of added vitamins and the precision of the method are given.

A collaborative study was carried out on one of the methods submitted to the Joint Economic Commission for Europe (ECE)/Codex Alimentarius Commission Group of Experts on the Standardization of Quick Frozen Foods for the determination of moisture in quick frozen french (fried potatoes. The method was based on the determination of loss of mass of the sample on drying in a convection oven 16 h at 103±2°C. Two samples of uncooked quick frozen french fried potatoes and 2 samples of oven quick frozen french fried potatoes were analyzed by 14 and 13 laboratories, respectively. The method is simple and was found to be analytically satisfactory with repeatability and reproducibility values of 0.21 and 2.00 g/100 g french fried potatoes, and 0.29 and 3.00 g/100 g oven french fried potatoes, respectively. The method was adopted by the Group of Experts in preference to other proposed procedures for this determination. The method has been adopted official first action by AOAC.