Poster Abstract No. 000630/1 In-source sample infusion for fully automated FD MS by H. Bernhard Linden LINDEN CMS GmbH, Auf dem Berge 25, D-28844 Leeste, Germany and Martin Maurer AMD Intectra GmbH, Königsberger Str. 1, D-27243 Harpstedt, Germany The Innovators in Magnetic Sector Mass Spectrometry Königsberger Straße 1 x D-27243 Harpstedt x Germany Phone: +49-4244-1062 / Fax: +49-4244-8646 E-mail: [email protected] http://www.amd-intectra.de O verview FD MS, the cleanest of the soft desorption ionisation techniques, has the stigma of not being suited to automation, requiring a skilled operator, yet effecting a low sample throughput. We present a new method and tool for automation of FD MS. FD-analysis of 33 FD-samples per hour is demonstrated with a maximum yield of 7 FD-samples in 10 minutes. A high FD-sample throughput is possible with an autosampler or robotic system and even if manually used. M ethods FIG. 1 shows a new FD-probe for automated supply (or quickest manual supply) of the sample solution to the whiskers of the FD emitter. A fused silica capillary ( 20 or 50 Pm, length ca. 600 mm) through the probe provides for transport of the sample solution to the emitter in the ion source in ion-optically optimum position. I ntroduction FD MS is the first, cleanest, and up to date softest desorption-ionisation technique giving abundant molecular ion signals of polar as well as non-polar samples. FI/FD MS is a standard tool in the petrochemical industry and increasingly a favoured one for analysis of compounds sensitive to hydrolysis or oxygen, or organo-metallics. With low fragmentation and not having matrix background noise, FD MS can seriously reduce spectral congestion of mixtures. Up to today, FD MS was notorious for being a difficult technique, requiring handwork, and not being suitable to automation. Well wetting and quickly evaporating solvents like methanol, ethanol, acetone, etc. are preferentially used. The source pressure raises slightly (to 2x10-4 mbar) going back to some 10-6 mbar within seconds. No additional pumping is needed in our MS. No sample is lost by spraying during sample adsorption and solvent evaporation. FIG 2 Whiskers touching the orifice of the fused silica capillary FIG. 1 In-source liquid injection FD-probe FIG. 2 gives an impression of how the whiskers touch the orifice of the capillary, resorb the eluting solution, distribute amounts of ca. 20 - 60 nl along the entire emitter wire, and are heated clean after desorption of the sample. Advantages of the FD-emitter remaining in the ion source during sample application: x Time consuming locking-in/-out of FDprobe for sample supply is dropped. x Focusing holds for all samples due to exactly identical emitter position x Risk of emitter breakage during sample application is enormously reduced. The Innovators in Magnetic Sector Mass Spectrometry Königsberger Straße 1 x D-27243 Harpstedt x Germany Phone: +49-4244-1062 / Fax: +49-4244-8646 E-mail: [email protected] http://www.amd-intectra.de R esults The new in-source liquid injection technique allows FD-analyses with a repetition rate of 30-40 FD-samples per hour. FIG. 3 shows continuously recorded FD-spectra of reserpine with repetitive sample applications every ca. 90 seconds FIG. 4 FD spectrum of PEG 600 FIG. 5 FD-spectrum of Si 69, the first liquid directly desorbed from the FD-emitter FIG. 6-7 FD and ESI spectra of clarithromycin for comparison Automation of injecting a sample, switching-on HV and EHC-ramp, recording spectra, switchingoff HV and EHC for injection of next sample allows competitive duty cycles and ease of operation. I nstrumentation The spectra are recorded with an AMD 604 double focusing magnetic sector mass spectrometer from AMD Intectra GmbH, Harpstedt. The FD source from Linden CMS, Leeste is installed in axis with the EI ion source of the AMD 604. This unique arrangement allows simultaneous recording of ions in FD and EI mode for accurate mass determinations as reported for ESI/EI. The FD-probe carrying the entire FD-ion source and the capillary, as well as the FDF 700 electronics from Linden CMS are the same as for usual FD. The FD-emitters from Linden CMS have 13 µm diameter central wires covered with billions of graphitic whiskers of ca. 60 µm length with optimized emission properties. The glassy beads have a suited hole for penetration of the capillary. Conclusion In-source liquid injection FD links an old desorption-ionization technique to modern automation preserving the specific merits of FD and providing reliable experimental conditions. The Innovators in Magnetic Sector Mass Spectrometry Königsberger Straße 1 x D-27243 Harpstedt x Germany Phone: +49-4244-1062 / Fax: +49-4244-8646 E-mail: [email protected] http://www.amd-intectra.de FIG. 3a TIC chromatogram of 33 FD-samples in 60 minutes repetitive injection of sample amounts of 15 - 60 fmol maximum yield: 7 FD-samples in 10 minutes FIG 3b Extended view of one injection Time table: injection of sample solution, evaporation of solvent at 2x10-4 mbar, pumping to 10-6 mbar till 40:08 40:08 HV and EHC-ramp switched-on (1 mA/s) 40:30 – 40:47 field-desorption of reserpine (at EHC of 22 – 39 mA) 41:12 HV and EHC-ramp switched-off 41:08 ready for next injection FIG 3c FD-spectrum of reserpine Single scan at maximum intensity The Innovators in Magnetic Sector Mass Spectrometry Königsberger Straße 1 x D-27243 Harpstedt x Germany Phone: +49-4244-1062 / Fax: +49-4244-8646 E-mail: [email protected] http://www.amd-intectra.de FIG. 4a FD - TIC chromatogram of PEG 600 (extended view) Time table: solvent has evaporated ca. 20 seconds after injection of sample solution, and vacuum is some 10-6 mbar Scan# 14: HV and EHC-ramp switched-on (1mA/s) Scan# 17-19: solvent inclusions desorb FIG. 4b FD-Spectrum of PEG 600 Scan# 25-38: field-desorption of PEG 600 (at EHC of 12 – 25 mA) Scan# 39-74 cleaning of the emitter surface Scan# 74 HV and EHC-ramp switched-off Scan# 69 ready for next injection The Innovators in Magnetic Sector Mass Spectrometry Königsberger Straße 1 x D-27243 Harpstedt x Germany Phone: +49-4244-1062 / Fax: +49-4244-8646 E-mail: [email protected] http://www.amd-intectra.de FIG. 5 FD-Spectrum of Si 69 first l i q u i d FD-spectrum FIG. 6 FD-Spectrum of Clarithromycin FIG. 7 ESI-Spectrum of Clarithromycin The Innovators in Magnetic Sector Mass Spectrometry Königsberger Straße 1 x D-27243 Harpstedt x Germany Phone: +49-4244-1062 / Fax: +49-4244-8646 E-mail: [email protected] http://www.amd-intectra.de