Identification and quantification of atractylenolide I and atractylenolide III in Rhizoma Atractylodes Macrocephala by liquid chromatographyion trap mass spectrometry

Rhizoma Atractylodes Macrocephala (RAM) is an important traditional Chinese medicinal herb that is used for treatment of dyspepsia and anorexia. The active ingredients, atractylenolide I (AO-I) and atractylenolide III (AO-III), were identified by direct-injection ion trap-mass spectrometry (IT-MS) for collecting MSn spectra. The major fragment ions of AO-I and AO-III were confirmed by MSn both in negative ion mode and in positive ion mode. The possible main cleavage pathway of fragment ions was studied. The determinations of AO-I and AO-III were accomplished by liquid chromatography (LC) with UV and MS. The analytes provided good signals corresponding to the protonated molecular ions [M+H]+ and product ions. The precursor ions and product ions for quantification of AO-III and AO-I were m/z 249231 and m/z 233215, respectively, using selected ion monitoring by LC-IT-MS. Two methods were evaluated for a number of validation characteristics (repeatability, limit of detection, calibration range, and recovery). MS provides a high selectivity and sensitivity for determination of AO-III and AO-I in positive mode. After optimization of the methods, separation, identification and quantification of the two components in RAM were comprehensively tested by HPLC with UV and MS. Copyright (c) 2012 John Wiley & Sons, Ltd.