解吸附-电喷雾离子化质谱方法快速检测啤酒中的甲基乙二醛

A desorption electrospray ionization mass spectrometry(DESI-MS) method was developed to determine methylglyoxal(MG) present in beers. This method utilized 1,2-diamino-4,5-dimethoxybenzene to convert MG to 6,7-dimethoxy-2-methylquinoxaline, and then determined the derivative by DESI-MS. 1×10^－5 mol•L^－1 MG in water and 5×10－5 mol•L^－1 MG in Yan Jing beer can be determined using this method. This time-saving method may provide a way for high-throughput analysis of MG in beverages.     

电喷雾解吸电离质谱法直接测定纺织品中致癌性芳香胺

Using a mixture of V (methanol):V (water):V (acetic acid)＝49:49:2, as the electrospray liquid, under optimized experimental conditions, as 24 kinds of carcinogenic aromatic amines on various texture of textile samples were fast directly detected by DESI-MS non-destructive. During analyzing actual sample, the mean analysis time for a single sample is about 30 s due to the method without the sample pretreatment, so it can save a lot of analysis time and improve the efficiency of the analysis. At the same time, the DESI-MS/MS has the elimination of false positive alert in virtue of the DESI-MS/MS of differentia. The method has a high sensitivity for analyzing most aromatic amines, with typical values ranges in a few 10^－9 g•kg^－1.     

电喷雾解吸电离质谱法测定表面痕量TNT

Rapid detection of trace amount of TNT on various surfaces was demonstrated using desorption electrospray ionization mass spectrometry without sample pretreatment. Under optimized working condition, the limit of detection was found around 0.1-10 fg as total amount, and the time consumed for single sample analysis was about 1.5 s.     

印迹膜电喷雾电离质谱法快速分析尿液中沙丁胺醇

沙丁胺醇(SAL)可促进动物生长,常被非法添加于畜禽饲料中,并可通过食物链进入人体,危害人体健康。目前,沙丁胺醇的分析方法已有很多报道,但对于复杂生物样本中沙丁胺醇的快速定量分析依然存在挑战。为实现这一目标,本研究采用印迹膜电喷雾电离质谱法(MIM-ESI MS)对尿液中的沙丁胺醇进行直接定性和定量分析。结果表明,该方法具有较高的灵敏度,尿液样本的检出限和定量限分别为5 ng/L和10 ng/L,在0.01~10 000 μg/L浓度范围内具有较好的线性关系。该方法无需样品前处理,其分子印迹膜材料具有特异性富集的功能,可实现生物复杂样本中痕量目标物的快速检测。     

电喷雾萃取电离和电喷雾电离所获一价正离子内能差异的比较研究

电喷雾萃取电离（EESI）和电喷雾电离（ESI）均属于软电离技术,但EESI比ESI更温和,能更好地保持蛋白质的构象。本研究以一价正离子为例,分别采用EESI和ESI技术对罗丹明B准分子离子m/z 443的裂解行为进行多级串联质谱研究,考察了不同碰撞能量对裂解行为的影响,建立了这两种离子源产生的离子内能差异（简称内能差异）的定量测定方法,并探讨了该方法的影响因素及适用范围。结果表明,EESI与ESI离子源的内能差异为11.5 eV。该方法可为其他不同离子源产生的离子内能差异比较提供基本思路,也可为深刻理解不同离子源产生离子的质谱行为提供参考。     

质谱电喷雾电离源研究新进展

自1984年约翰芬恩(John Fenn)发明一种软电离离子源,即电喷雾电离源(ESI)以来,促进了质谱技术在大分子分析领域,特别是生物大分子领域的广泛使用。ESI源的低取样效率由ESI源的离子化效率和传输效率的构成,制约着ESI源质谱灵敏度的提高,因此研究者们一直努力改进ESI源的性能,以提高取样效率、改善ESI源质谱灵敏度。本研究介绍了ESI源的原理,并评述了近年来ESI源研究的新进展和应用。     

MyoglobinEncapsulatingLiposomeCombinedwithMatrixAssistedLaserDesorption/IonizationMassSpectrometryforTraceProteinDetection

Detection of immunoglobin G antibodies(IgG) is a very common form of medical diagnostics for viral hepatitis, autoimmune hepatitis and cirrhosis. Development of a reliable and sensitive method for the detection of IgG is hence essential. In this study, myoglobins, serving as a mass tag, were encapsulated in liposomes conjugated with 10-20 monoclonal anti-human IgG for the detection IgG. These bi-functional liposome-anti-IgG complex were subsequently incubated with increasing concentrations of IgG antibodies. The IgG and the mass tag were released by the addition of 25 mM cyano-4-hydroxycinnamic acid to the liposome complex. The results showed that IgG were captured and concentrated in the liposomes, and could be indirectly but reliably quantified by measuring the hemin release from myoglobin via mass analysis. Hemin is a small molecule that can be detected easily without mass discrimination and ion suppression. The amplification effect of this immunoassay can be assessed by measuring the number of hemin released per IgG protein. The use of those bi-functional liposomes was 100 times more sensitive compared to the conventional MALDI-TOF MS analysis. These results demonstrated the potential of myoglobin-encapsulated and antibody receptor-conjugated liposomes in lowering detection limits of both IgG and possibly other antibodies, and increasing the sensitivity of mass analysis for large molecules.     

利用HPLC-MS/MS技术进行羟自由基检测的分析方法研究

Hydroxyl radical (•OH) can cause severe damage to cells and tissues. However, its analysis is very difficult for its high reactivity and very short life. This paper present a HPLC-MS/MS method for indirectly detecting •OH by determining DMPO-OH, its addut with spin trap DMPO ( 5,5-dimethyl-1-pyrroline N-oxide ), with the N-Methyl-2-Pyrrolidone (NMP) used as internal standard. The ratio of the peak area of the DMPO-OH and NMP negatively correlate with the concentration of •OH. The results show that the method is simple, rapid, precise in both the determination of •OH and evaluation of •OH scavenging activities of antioxidants.     

液相色谱-串联质谱法测定尿液中的可替宁

为了准确测定吸烟者与非吸烟者尿液中可替宁含量水平,建立了液相色谱-串联质谱（LC-MS/MS）测定方法。尿液经稀释、离心和过滤,引入LC-MS/MS,经Agilent Zorbax Eclipse XDB-C₁₈色谱柱（150 mm×2.1 mm,3.5 μm）分离,以0.1% 甲酸水溶液0.1% 乙酸甲醇溶液为流动相,采用梯度洗脱方式,以电喷雾离子源正离子多反应监测模式进行分析。方法检出限为0.08 μg/L,线性范围为1~500 μg/L,空白样品中加标回收率范围在94.3%~99.9%,精密度（以相对标准偏差计）为0%~3.2%。利用此方法检测了58个非吸烟者和246个吸烟者尿液中可替宁的含量水平,结果表明：吸烟者24 h尿液中的可替宁含量是非吸烟者的180多倍,但是由于个体之间以及吸烟行为之间的差异,尿液中的可替宁含量并不随卷烟主流烟气中烟碱含量的升高而升高。     

毛细管进样-激光解吸电离气溶胶飞行时间质谱仪检测超细纳米颗粒物化学成分

采用毛细管大气压进样接口,结合激光多光子解吸、电离等技术,自行研制了毛细管进样-激光解吸电离气溶胶飞行时间质谱仪,用于在线测量超细纳米颗粒物的化学成分。应用商品化的气溶胶发生器和自制的离子诱导成核反应器,在实验室内分别产生了KCl、NaCl、NaI/NaBr混合物和Air/H₂O/SO₂混合气体成核反应的粒径小于100 nm的超细纳米颗粒物,并通过质谱仪获得了它们的化学成分信息。结果表明,相对于具有较大粒径的颗粒物,超细纳米颗粒物在激光多光子电离过程中更容易完全原子化电离,但通过改善激光的聚焦条件可以获得超细纳米颗粒物成分的分子信息。实验测量了毛细管大气压进样接口传输超细纳米颗粒物的效率,为0.33%,与国际同行采用类似大气压进样接口传输气体分子的效率一致。     

电喷雾萃取电离源调节装置的研制

电喷雾萃取电离（EESI）源具有样品无需复杂预处理、易于集成和小型化、可与多种商用质谱仪联用、适于现场分析等特点,已在生命科学、环境、食品、国防、刑侦等领域的复杂基体样品的直接质谱分析领域得到了广泛应用。然而,实验室制作的普通EESI源长期稳定性较差,空间位置难以精确调节,针对此问题,本工作研制了EESI源的调节装置。在优化离子源空间位置参数与仪器参数的条件下,安装该调节装置后,采用EESI源对脯氨酸进行检测,检测限由0.5 μg/L降至0.075 μg/L,并对肺癌患者血样中的缬氨酸、苯丙氨酸、脯氨酸、组氨酸、赖氨酸、天冬酰胺、天冬氨酸、苏氨酸、酪氨酸和谷氨酰胺进行连续5日检测,各样品的平均RSD均小于10%。实验证明,该调节装置具有操作简单、稳定性高、适应范围广等特点,对EESI离子源的性能有较大提高。     

影像测量法辅助电喷雾萃取电离源喷头的研制

电喷雾萃取电离（EESI）源具有无需样品复杂预处理、易于集成和小型化、适于现场分析等特点,是近年来研究的热点。喷头孔是影响EESI源性能的关键部件。然而,因喷头孔几何参数非常小,使用常规方法无法对其进行精确地检测与评估,一直无法满足EESI源的要求。本工作开发了一种基于影像测量的检测与评估方法,通过提取喷头孔的几何轮廓坐标参数,对比分析两种工艺制造的喷头孔的直径与圆度误差。在优化仪器参数的条件下,采用新工艺制造的EESI源对甲基苯丙胺进行检测,检出限从0.101 μg/L降至0.041 7 μg/L,RSD从0.9%～5.8%降至0.6%～4.2%,实验结果与采用影像测量法的评估结果一致。采用新工艺制造的EESI源对尿液中的可待因、海洛因、氯胺酮、苯丙胺、咖啡因、麻黄碱、甲基苯丙胺、地西泮、戊巴比妥和舒乐安定进行连续5日检测,各样品的最大RSD均小于5.2%。结果表明,该影像测量法可缩短EESI源研制周期、降低成本,EESI源的稳定性与灵敏度可得到较大提高。     

电喷雾萃取电离质谱直接测定啤酒中多种氨基酸

A novel method was developed for directly detection of amino acids in beer by using extractive electrospray ionization mass spectrometry (EESI-MS) without any sample pretreatment. Taking the advantage of multiple-stage tandem MS capability of an ion trap mass analyzer, all the signals detected from beer samples were quickly identified using their characteristic fragments, resulting in confident validation of the analytical results. The average time for a single sample analysis was less than 0.5 min, and the relative standard deviations of the method were in the range of 5.0%-10.0%. The limit of determination of this method was found to be 10^－10 g•mL^－1 for most amino acids.     

电喷雾质谱剖析烷基多苷的组成与

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