摘要

A new method based on reversed phase high performance liquid chromatography ( HPLC), positive ion electrospray time-of-flight mass spectrometry (ESI-TOF/MS) has been developed for the characterization of insulin in commercial insulin injection. With reversed phase C, microcolumn (2. 1 min x 30 mm, 3. 5 mu m) and water and acetonitrile (66:34, V/V) containing 1% HAc as mobile phase, insulin and other compounds could be separated rapidly within I min. The factors including flow rate, pH, fragmentor affecting the MS signal of insulin have been optimized. Under the optimum conditions, insulin could be ionized efficiently and only 0.174 pmol sample was required to satisfiy the quantitative analysis of insulin. Meanwhile, MS peaks with + 3, + 4, + 5, + 6 and + 7 charges were formed in mass spectrum under the ESI positive scan mode. After deconvolution analysis, the exact mass of insulin in different samples could be obtained. Compared to the theoretical mass, the relative error of the mass could be down to 1.72 x 10(7).