PHOSPHATE-GRADIENT HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC METHOD FOR THE ANALYSIS OF SYNTHETIC SALMON-CALCITONIN

A gradient reversed-phase high-performance liquid chromatographic method was developed for the quantitative analysis of salmon calcitonin. A 0.054-M potassium monobasic phosphate buffer was modified with an acetonitrile-methanol (4:1) mixture as the mobile phase. Several gradient slopes are used during the separation and analysis so that potential peptidal component impurities in salmon calcitonin samples can be separated without wasting analysis time. The method is applicable to the determination of salmon calcitonin in the peptide portion of the sample as well as in the total sample. The analytical results are expressed as percent chromatographic purity instead of activity units.