质谱分析-2013

1、Particulate Matter accumulation due to knife-edge vortexCone - acts as a physical barrier Keeps heated transfer tube face cleanESISample plate 600 800 1000 1200 1400 1600 m/z266 nm355 nm532 nm Laser Wavelength Effects Des Arg1BradykininAngiotensin I-Bag Cell Peptide1-8 Pulsed Nd:YAG laser 2 mW at 10

2、 Hz 266, 355, 532 nm wavelengths Optics not optimized for IR-MALDI Wavelength dependence but not shown here 200 22 400 600 800 Mass (m/z)LGAGGYFL-EnkA2L5R6-Enk123545432110 pmol mix, + ion10 pmol mix, - ion1pmol mix, - ion, PBS (pH 7)1pmol mix, - ion, TRIS (pH 9) Ion Mode and pH Effects + ion mode “c

3、ontaminants”- HxCy (air, storage cont, vacuum) - Mx+ (air, storage cont, solvents)- ablated Si clusters analyte supression below 800 m/z no advantage over MALDI! - ion mode w/ or w/o buffering contaminants as pH 600 800 1000 1200 1400 1600 Mass (m/z) Methanol, 6 days Dry air, 6 days H2O/(H2O + Metha

4、nol)0.20.40.60.80.01.0Contact Angle 020406080100Dry air, 1 dayMethanol, 1 dayDry air, 6 daysMethanol, 6 days Solvent Effects in Storage and SamplingDes Arg1BradykininAngiotensin I-Bag Cell Peptide1-8 Hydrophobicity decreases w/ storage (contact angle analysis) Methanol storage “preserves” surface (DIOS-MS analysis)Substrate DropletContact Angle1 Torr10 l/s10-2 TorrQ1Q3Q210-6 Torr10-3 Torr供气系统气相色谱主机连接系统质谱检测仪二、二、LC-MS LC对分离热不稳定物质较GC好，LC-MS联用最主要的是