LCMS(ESI)的基本原理及应用.ppt

* ) * * Over the past several decades, a number of different LC/MS interfacing techniques have been developed in an effort to address the requirements of an ideal LC/MS interface. The two relatively recently developed and closely related Atmospheric Pressure Ionization (API) techniques of APCI and API-Electrospray together encompass by far the broadest range of analyte polarity and molecular weight. These techniques also provide superior sensitivity and robustness compared to older techniques such as thermospray, particle beam, and FAB. For these reasons, APCI and Electrospray have rapidly become the predominant LC/MS interfaces. It is important to note that many analytes will work by either interface! * The steps need to be clearly labeled so that the student understands the order in which they happen. These slides need to be approached from the point that these settings are for the Agilent Trap which has different ionization characteristics than that of a LCQ Deca. The users we get will be LCQ users that have lots of experience with LCQs and possible experience with the Quad MSD system. For Instructor Notes * * Column: Supelcosil ABZ+Plus 5 μm, 2.1 mm x 250 mm (Supelco) Column temperature: 40 °C Mobile phase: isocratic at 25% A in B A: Acetonitrile (MeCN)  B: 5 mM TDFHA in waterFlow: 0.2 ml/min Injection: 500 μl Ionization: Electrospray positive ion mode Fragmentor: 80 V Nebulizer: 60 psig nitrogen Drying gas: 10 l/min nitrogen at 350 °C The developed method was an efficient and reliable means for the quantitation of three pesticides in river water. Tridecafluoroheptanoic acid (TDFHA) was the most useful volatile ion-pairing reagent based on sensitivity and separation of the three pesticides. The recovery in river water ranged from 88.5 to 97.5% and RSDs ranged from 3.3 to 4.2% (0.5 ng/ml). The method was linear from 5 to 0.1 ng/ml with correlation coefficients ranged from 0.997 to 0.999. The detection limit ra