生物质谱作为SNP分型检测方法的研究

利用改良的 Miller法从人血中提取人类基因组 DNA。采用聚合酶链式反应 ( Polymerase chain reac-tion,PCR) ,对含有单核苷酸多态性 ( SNP)点的 DNA片段进行扩增 ,然后用 CIP和 Eox I去除掉 PCR体系中剩余的脱氧核糖核苷三磷酸 ( d NTP)和引物 ,最后用单碱基延伸反应获得 SNP位点处碱基类型。用基质辅助激光解吸电离 -飞行时间质谱 ( MALDI-TOFMS)或电喷雾电离 -四极杆飞行时间质谱 ( ESI-Qq TOFMS)检测延伸产物与未延伸引物间的分子量差异 ,确定该点处碱基。对不同的生物质谱检方法以及生物质谱检测方法与其它检测方法的优缺点进行了分析比较     

乳酸左氧氟沙星的飞行时间质谱裂解规律研究

采用不同电子能量的 EI和不同反应气压力的 CI电离方式 ,研究了乳酸左氧氟沙星 ( LL)的半水合物飞行时间质谱 ( TOFMS)的裂解规律。结果表明 :乳酸左氧氟沙星难以产生喹诺酮特有的裂解产物 ;当电离能量为 2 5 e V时 ,所得 EI谱的碎片离子丰度明显大于 70 e V所得离子的丰度 ;当反应气由正常压力 1× 1 0 -2Pa降低到 1× 1 0 -3 Pa时 ,CI谱中碎片离子丰度由极小变大 ,其强度与 EI( 70 e V)所得离子丰度相当     

Aroma profiles of five basil (Ocimum basilicum L.) cultivars grown under conventional and organic conditions

A headspace solid-phase microextraction (HS-SPME) method coupled to gas chromatography–ion trap mass spectrometry (GC–ITMS) has been developed and applied for profiling of volatile compounds released from five Ocimum basilicum L. cultivars grown under both organic and conventional conditions. Comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC×GC–TOFMS) was employed for confirmation of identity of volatiles extracted from the basil headspace by SPME.     

新型静电离子导入器的研制

A novel electrostatic ion guide(EIG) was designed and manufactured according to the simion simulation. Favorable focusing effect with high transmission efficiency was achieved by optimizing different parameters. EIG was used to ensure the vacuum difference between electrospray ionization(ESI) and time of flight mass spectrometry(TOF MS), and achieve ion-neutral molecular separation as well.     

全二维气相色谱/飞行时间质谱对饱和烃分析的图谱识别及特征

采用全二维气相色谱/飞行时间质谱分析方法对典型石油样品中饱和烃组分进行了定性分析,依据极性大小和环数多少的分布特征,解析了点阵图谱中的烷烃、单环烷烃、双环烷烃、单金刚烷和双金刚烷系列、三环萜烷类、甾烷类和藿烷类等生物标志化合物的识别;讨论了典型生物标记化合物单金刚烷、三环萜烷和藿烷类的全二维点阵谱图特征;检测到过去GC/MS分析中常被忽视的C₃₁~C₃₅三环萜烷,为石油地质实验和研究提供了参考依据。全二维气相色谱/飞行时间质谱相比于GC/MS灵敏度更高、峰容量更大,适合复杂混合物体系的分析,对石油样品的分析有很好的应用前景。     

HPLC-TOFMS测定NG/TEGDN中的丙三醇二硝酸酯

应用高效液相色谱飞行时间质谱联用技术( HPLC-TOFMS)测定了丙三醇三硝酸酯(NG)/二缩三乙二醇二硝酸酯( TEGDN)混合硝酸酯中的杂质丙三醇二硝酸酯.色谱条件为Gemini5 μC-18色谱柱、55/45 (V/V)的甲醇/水流动相;质谱采集模式为电喷雾源负离子方式.结果表明:丙三醇二硝酸酯来源于NG,它存...     

高分辨飞行时间质谱仪的原理及设计

讨论了影响飞行时间质谱仪分辨率的因素,包括基质辅助激光解吸离子化所产生的对分辨率的影响因素。参照近代文献资料,提出了自行设计制造的飞行时间质谱仪的基本设计方案,指出这种仪器在我国的应用前景。     

飞行时间质谱仪射频四极杆驱动器的研制

针对自制垂直引入式飞行时间质谱仪（orthogonal extraction time-of-flight mass spectrometer, O-TOFMS）的需要,运用直接数字频率合成 (direct digital frequency synthesis,DDS)技术,研制了射频四极杆的高压射频驱动电路装置。该驱动器频率可调范围为0.5~2 MHz,幅度最高达到1 000 Vp-p。该射频四极杆驱动器（radio frequency quadrupole driver,RFQ Driver）可用于分子离子反应器（molecule ion reactor,MIR）和RFQ驱动,其结构简洁、成本低、性能稳定可靠。     

样品靶自动定位大气压基体辅助激光解析离子源的研制

本文介绍实验室自制的样品靶可以自动定位的大气压基体辅助激光解析离子源(Atmospheric Pressure Matrix Assisted Laser Desorption/Ionization,AP-MALDI)的原理、结构,以及与飞行时间质谱仪(Time of flight Mass Spectrometer,TOFMS)联用对多肽样品的分析实验。所得到的生物大分子谱图表明:AP-MALDI离子源与高分辨TOFMS联用可以实现大气压下大分子高通量的精确质量检测,最低检测限可达2.5fmol。     

Application of electrospray ionization ion trap/time-of-flight mass spectrometry for chemically-synthesized small RNAs

In this study, we have demonstrated an accurate and rapid small RNA analytical method with both sequence determination and detailed modification analysis by electrospray ionization-ion trap/time-of-flight mass spectrometry (ESI-IT/TOFMS). To develop this ideal method, we have examined the performance of ESI-IT/TOFMS using various chemically-synthesized model sequences of modified or unmodified microRNAs (miRNAs). The deconvoluted mass of a 22-nucleotide (nt) miRNA was obtained from a multiply charged precursor ion (MS(1)). The ion exhibited high mass accuracy (< 7 ppm) and high mass resolution (a value of m/Δm=10,000) and was therefore very useful in RNA composition assignment. The optimized MS(2) method using ion trap collision-induced dissociation, as well as automatic annotation analysis of product ions based on the accurate mass information, enabled the precise sequencing determination of intact miRNAs. Further, the detailed structural analysis of 3'-terminal modified nucleic acid in intact methylated miRNA was carried out using the MS(3) capability of the hybrid IT/TOFMS. The direct infusion method also provided a high throughput and good sensitivity because the analytical time and sample concentration needed in a series of experiments with reliable data were only 3 min and 100 nM, respectively. This study provides a novel approach for characterizing the intact chemically-synthesized small RNA without chemical and enzymatic digestions and would be widely applicable for the structural analysis of complicated modified small RNAs.