Direct infusion (DI) electrospray ionization quadrupole time-of-flight (Q-TOF) mass spectrometry was applied to analysis sixteen compounds from traditional Chinese medicines (TCMs). Characteristics of these compounds in electrospray ionization mass spectrometry (ESI-MS) and in MS/MS were observed to know the differences of ionization capacity and dissociation characteristics of structurally different compounds. The observation indicated that in order to maximize numbers of constituents detected, it is necessary to analyze sample in both positive and negative mode. The existence of carbonyl group in structure seems to be a factor that favors the formation of quasi-molecular ion (QMI) or other adduct molecular ion (OAMI) in positive mode. When cone voltage was 30V, most compounds could form mass spectral peaks of QMIs or OAMIs. However, in-source collision-induced dissociation (CID) seemed unable to be completely avoided by altering cone voltage. Analysis was recommended at three different cone voltages of 10V, 30V and 50V. MS/MS was proved to be an effective way to obtain additional structural information because fragment ions were observed for all QMIs and OAMIs in MS/MS. The developed method has been successfully applied in our study on Si-Wu-Tang. The method is useful for quick qualitative analysis of constituents in mixture samples of TCM.%采用直接输注电喷雾电离质谱对十六种中药来源的化合物进行了分析.观察了它们的电喷雾电离质谱和串联质谱特征,以了解不同结构化合物的电离能力和裂解特点.观察表明:为使样品成分尽可能多地被检测,必须同时进行正负两种模式的分析.化合物结构中羰基的存在似有利于化合物在正离子模式下形成准分子离子或其它分子加和离子.当采样锥电压为30 V时,大多数化合物能形成准分子离子或其它分子加和离子.但改变采样锥电压似不能完全避免源内裂解.建议分析时同时考察不同采样锥电压(如10 V、30 V和50 V).串联质谱分析被证明是获得进一步结构信息的有效手段,因为对于所有被观察的准分子离子和其它分子加和离子,均能在串联质谱分析中检测到碎片离子.本研究在四物汤的研究中已经成功地运用了该方法.此方法有助于中药混合物中样品成分的快速定性分析.
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