Figure 2: Selectivity of the method is evident from the chromatograms. The black chromatogram was obtained with the solution 1 (PGE1 at 15 μg/ml); the pink chromatogram was obtained with the solution 2 (PGA1 at 7.125 μg/ml) and the blue chromatogram was obtained with the solution 3 (mixture of solution of PGE1 at 15 μg/ml and PGA1 at 7.125 μg/ml).