龙胆质谱指纹图谱及化学模式识别方法研究

利用电喷雾质谱(ESI-MS)法建立龙胆质谱指纹图谱,研究其中代表性裂环烯醚萜苷类成分的ESI-MS 规律。采用甲醇超声法提取龙胆中裂环烯醚萜苷类成分,在正离子方式检测模式下直接进样,应用一级全扫描质谱建立其特征图谱。运用化学模式识别方法对图谱数据进行分析,发现秋季龙胆样品的聚集程度优于春季龙胆样品,根据春季、秋季药材样品的差异,可以对采收期进行区分;裂环烯醚萜苷类成分在二级质谱中易发生脱水、乙酰基、葡萄糖基等。电喷雾质谱法的精密度、稳定性、重现性均符合要求,且具有特征性强、分析速度快、样品用量少等优点。     

液质联用技术分析精氨酸双糖苷对麦芽糖酶的抑制活性

Maltulosyl arginine is the initial maillard reaction product of maltose and arginine, which may have anti-diabetic activity. In this study, LC/MS was combined with ultrafiltration as a new method to investigate its inhibitory activity on maltase. The quantitative data was got from a triple quadrupole instrument in multiple reaction monitoring (MRM) mode. The experimental results proved that maltulosyl arginine is an effective maltase inhibitor and can be used for the treatment of diabetes and obesity.     

气相碱度与质子亲合势的基本概念及其测定方法

介绍了气相碱度和质子亲合势的基本概念 ,对气相碱度及质子亲合势的测定方法进行了详细评述 ,包括 :电离阈值法、理论计算法、气相平衡常数法、插入法、动力学法、热力学法等。列出相关文献近 4 0篇     

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.     

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...     

二甘醇单叔丁基醚合成产品的色谱—质谱分析

本文作者采用色谱—质谱联用法定性地分析了合成的二甘醇单叔丁基醚及其它副产物,并用质谱谱图解析方法确定了它们的结构。     

酒黄连的电喷雾质谱研究

Using ESI-MS, adding of different weight yellow wine and different roasting temperature of prepared Coptidis Rhizoma were investigated. The results were that the influence adding of different weight yellow wine on the content of alkaloids was little, but the roasting temperature was reverse. This study offers a perspective of the technique of prepared Coptidis Rhizoma .     

[C12H8]^2＋离子中电荷定位的理论研究

本文用半经验量子化学方法ＭＮＤＯ研究了由联苯衍生物产生的［Ｃ１２Ｈ８］２＋双电荷离子的结构，讨论了其中的电荷定位和影响离子稳定性的因素，双电荷离子的两个电荷分别定位于两个苯环上，表明该离子是由联苯衍生物经两步反应产生。     

甘遂炮制的电喷雾质谱研究

应用电喷雾质谱(ESI-MS)技术,根据甘遂中巨大戟二萜醇型化合物在质谱中离子强度的变化情况,采用正交实验法,优化甘遂药材醋炒和醋烘两种炮制工艺的最佳炮制条件,并提出醋烘法的炮制工艺。实验结果表明:醋炒最佳炮制条件为30%醋量,闷制24h,100℃炒25min;醋烘最佳炮制条件为30%醋量,闷制24h,110℃烘40min。     

DART-Q-Orbitrap MS法快速检测豆制品中碱性橙Ⅱ和金胺O

采用实时直接分析(direct analysis in real time,DART)离子化技术与四极杆-静电场轨道阱高分辨质谱联用技术(Q-Orbitrap MS),建立了快速定性和定量分析方法,检测豆制品中非法添加的碱性橙Ⅱ和金胺O。在正离子模式下,采用Full MS/targetrd-MS2扫描方式,可直接将豆制品置于离子化区域内对两种染料进行快速定性分析。在定量分析中,采用80%乙腈水溶液提取样品,应用Dip-it载样方式,对实验参数进行系统性优化。采用空白基质溶液进行梯度稀释,测得碱性橙Ⅱ和金胺O在基质中的检出限均为0.2mg/L;采用内标法定量,在1～20mg/L浓度范围内线性关系良好,相关系数分别为0.997 2和0.999 4。该方法快速准确,可为食品中非法添加染料的定性和定量检测提供参考依据。