B:
Dilute a portion of the Syrup with water to obtain a test solution containing about 0.4 mg of calcium per mL. Prepare a Standard solution in water containing 2 mg of calcium gluconate and 4 mg of calcium lactobionate per mL. Apply separately 5 µL of the test solution and 5 µL of the Standard solution to a suitable thin-layer chromatographic plate coated with 0.25-mm layer of chromatographic silica gel (see
Chromatography 621). Dry the plate in a current of cool air. Place the plate in a suitable chromatographic chamber lined with filter paper and previously equilibrated with a solvent system consisting of a mixture of alcohol, water, ethyl acetate, and ammonium hydroxide (50:30:10:10). Develop the chromatogram until the solvent front has moved about three-fourths of the length of the plate. Remove the plate from the chamber, and dry at 100
for 20 minutes. Allow to cool, and spray with a spray reagent prepared as follows: Dissolve 2.5 g of ammonium molybdate in about 50 mL of 2 N sulfuric acid in a 100-mL volumetric flask, add 1.0 g of ceric sulfate, swirl to dissolve, dilute with 2 N sulfuric acid to volume, and mix. Heat the plate at 110
for about 10 minutes: the two principal spots obtained from the test solution correspond in color, size, and
RF value to those obtained from the Standard solution.
[NOTESucrose, if present in the test solution, appears in the chromatogram as a spot between two principal spots.
]