Determination of aristolochic acids in medicinal plant and herbal product by liquid chromatography–electrospray–ion trap mass spectrometry

Abstract

This paper describes a liquid chromatography–electrospray–ion trap mass spectrometry (LC–ES–ITMS) method for the determination of aristolochic acid I and II (AA-I and AA-II) in medicinal plants and Chinese herbal remedies. A reversed phase C 18 column with gradient elution was utilized. The effects of mobile phase additives, acetic acid and ammonium acetate, on LC separation and ES ionization were investigated. For both AA-I and AA-II, the [M+NH 4] + ion was found to be the precursor ion for target MS/MS analysis. The MS/MS product ion, [M+H−44] +, was used for the quantitative measurement of AA-I and AA-II. The linearity was good from 0.03 to 5 μg ml −1 and good correlation ( r 2=0.999) over the range examined was determined for both AA. The detection limit based on a signal-to-noise ratio of three was 0.012 and 0.015 μg ml −1 for AA-I and AA-II, respectively. Various Chinese herbal remedies obtained from renal failure patients and medicinal plants were examined by this newly developed method.