Quantitative analysis of synthetic human calcitonin by liquid chromatography-mass spectrometry.

The quantitative analysis of synthetic human calcitonin (hCT) by micro-liquid chromatography-electrospray ionization mass spectrometry (micro-LC-ESI-MS) is reported. hCT was extracted from plasma by an immobilized antibody column and separated by a micro-LC system. The molecular mass of hCT is 3417, and m/z 1140, corresponding to the [M + 3H]3+ ion, was observed by ESI-MS. This ion was monitored in the selected-ion monitoring mode; rat calcitonin, which is highly homologous to hCT, was used as an internal standard. The calibration curve for the quantification of hCT was linear in the range 10 ng/ml to 1 microgram/ml of plasma.