Sensitive, Selective, Precise and Accurate LC-MS Method for Determination of Clonidine in Human Plasma

A selective and sensitive liquid chromatography-mass spectrometric method in ESI (+ve) mode was developed and validated completely in human plasma. Clonidine and IS, carbamazapine, were extracted from human plasma via liquid-liquid extraction with ethyl acetate. Following evaporation under nitrogen, the residue was reconstituted with mobile phase and analyzed using API 4000 LC-MS-MS system. An isocratic program with binary mobile phases (0.1% formic acid in water and acetonitrile) was used to separate interference peaks by a C18 analytical column. Linearity range was 0.49-73.98 ng mL⁻¹. The intra- and inter-day accuracy and precision were within acceptable limits (