北五味子的超临界萃取及产物的HPLC-APCI-MS/MS分析

优化超临界流体萃取北五味子中木脂素类成分的提取工艺,对萃取物中所含有效成分的归属进行分析鉴定.以五味子总木脂素为评价指标,采用正交实验法和不同影响因素系统考察法对CO2 -SFE萃取北五味子中木脂素类成分提取工艺进行优化,利用液相色谱-大气压化学电离质谱联用法(HPLC-APCI-MS/MS)分析鉴定产物结构.确定了最...     

三聚氰胺的基质辅助激光解吸/电离飞行时间质谱分析

Oxidized carbon nanotubes are tested as the matrix for analysis of the melamine by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS). Traditional MALDI matrix are not suit for analysis of the low molecular compounds due to the interference associated to the matrix clusters. Oxidized carbon nanotubes can transfer energy to the analyte under the laser irradiation, which makes analyte well ionized or desorbed. Moreover, the interference of the intrinsic matrix ions can be eliminated. Melamine as the a toxic additive which had been added in the milk powder, then it is necessary to establish a new method for detection of the melamine rapid and sensitive.     

玫瑰花中挥发油成分的超临界萃取及质谱分析

提取并分析了吉林省珲春产冷香玫瑰和四季红玫瑰的挥发油成分。利用超临界CO₂流体萃取技术进行提取分离,并通过正交实验确定最佳萃取工艺，用气相色谱 质谱（GC/MS）联用技术对其成分进行分析。萃取最佳工艺为：萃取压力20 MPa，分离压力7 MPa，萃取温度35 ℃，分离温度40 ℃。得到的挥发油通过GC/MS分析并与标准谱库进行对照检索，得出冷香玫瑰中含有76种挥发油成分，相似度在65%以上的29种；四季红玫瑰含有78种挥发油成分，相似度在65%以上的有19种。超临界CO₂流体萃取玫瑰花中挥发油成分方法简便、快速、高效；两种玫瑰所含挥发油成分不同，可能是其香气不同的主要原因。     

山楂叶总黄酮中α-葡萄糖苷酶抑制剂的超滤质谱筛选研究

In vitro α-glycosidase inhibition assays and Ultrafiltration LC-DAD-ESI-MSⁿ were combined to screening α-glucosidase inhibitors from hawthorn leaves flavonoids extract. As a result, hawthorn leaves flavonoids extract showed strong α-glucosidase inhibitory activity, four compounds presented α-glucosidase inhibitory effects were observed and identified by LC-DAD-MSⁿ, and further confirmed by high resolution SORI-CID FT ICR MS data.     

头孢菌素类抗生素的电喷雾多级串联质谱分析

采用电喷雾多级串联质谱技术,对头孢呋辛、头孢噻吩钠、头孢硫脒、头孢噻利、头孢西丁钠五种头孢菌素类抗生素进行了系统研究,总结了该类化合物的电喷雾质谱特征断裂机理。该类化合物在电喷雾正离子或负离子模式下,均发生C-3位侧链C-X(X=O、N、S)键的特征断裂,为头孢菌素类抗生素化合物结构鉴定提供了新方法。在负离子模式下,头孢呋辛二级质谱中β-内酰胺环发生开环断裂,与文献结果一致;在电喷雾正离子模式下,头孢噻吩钠、头孢噻利、头孢西丁钠多级串联质谱中均失去C-7位侧链上一分子CO。