Analysis of underivatized alditols in traditional Chinese medicines by liquid chromatography–tandem mass spectrometry based on ligand exchange chromatography

Alditols are potential chemical markers in traditional Chinese medicine for quality control purpose. For example, mannitol is one of the major compounds in Cordyceps sinensis . Galactitol is the proposed marker compound of formulated oral traditional Chinese medicine liquid “Fufangfufangteng Heji.” Development of a highly selective analytical method for unambiguous identification of selected alditols is of prime importance to assure the quality of these valued and precious traditional Chinese medicines. In this study, a liquid chromatography–tandem mass spectrometry method based on ligand exchange chromatography was developed to analyze and identify underivatized alditols such as galactitol, mannitol and sorbitol in different traditional Chinese medicines. The limits of detection of these alditols ranged from 0.7 to 1.4 mg/kg. The limits of quantification of these alditols ranged from 2.3 to 4.6 mg/kg. The method has been applied in the detection of alditols in various samples such as Cordyceps sinensis , Cordyceps militaris , and concentrated granule of Radix Celastrus orbiculatus . The results indicated that several underivatized alditols could be identified rapidly and unambiguously by liquid chromatography–tandem mass spectrometry on ligand exchange chromatography column.