麻痹性贝毒素电喷雾质谱负离子模式分析特征

利用多级质谱技术对8种常见麻痹性贝毒素（GTX1, GTX 4, GTX2, GTX 3, dcGTX2, dcGTX3, C1和C2）在电喷雾质谱负离子模式下的分析特征进行研究。结果表明:8种目标化合物在一级质谱分析过程中均易失去1个H，形成准分子离子M-H]^-峰（基峰）；在二级质谱分析过程中，各化合物的母离子（M-H]^-）主要通过丢失-H₂O和-NHCO等中性碎片，形成稳定的特征子离子峰，并且同分异构体的二级质谱图有差异，可为含硫麻痹性贝毒素的二级质谱定性、定量分析提供依据。此外，对各目标化合物二级质谱的主要碎片峰进行三级质谱分析，对产生的主要特征碎片峰进行归属，并推测裂解途径。本研究可为电喷雾质谱在负离子模式下检测含硫麻痹性贝毒素提供参考和依据。

MS Characteristic of Paralytic Shellfish Poisoning Toxins Detected by Electrospray Ionization Mass Spectrometry in Negative Ion Mode

The MS characteristic of eight common paralytic shellfish poisoning (PSP) toxins (GTX1, GTX4, GTX2, GTX3, dcGTX2, dcGTX3, C1 and C2) were investigated by electrospray ionization multi-stage mass spectrometry (ESI-MSⁿ) in negative ion mode. The results show that the quasi-molecular ion peak M-H]^- (base peak) of each PSP toxin is detected by ESI-MS. Stability characteristic fragment ions are observed by the neutral loss of -H₂O and -NHCO for ESI-MS² detection， and the MS² spectra of PSP toxin isomers are different, which can provide experimental basis for qualitative and quantitative determination of sulfur containing PSP toxins by ESI-MS². ESI-MS³ detection is performed for the main characteristic fragment ions of the target toxins produced during ESI-MS² analysis. The main MS³ characteristics of the fragment routes are also discussed. This study can help to offer the reference and basis for determination of sulfur containing PSP toxins by electrospray ionization mass spectrometry in negative ion mode.