Specimen descriptions of experimental conditions for each of the facility’s instruments are given below for inclusion in your publications. For additional information, please contact the facility manager. Please acknowledge use of the facility’s instrumentation when using results for publication purposes.

FAB-MS

“FAB mass spectra were obtained using a VG70S double focusing magnetic sector mass spectrometer (VG Analytical, Manchester, UK, now Micromass/Waters) equipped with a Xe gas FAB gun (8kV @ 1.2mA), an off-axis electron multiplier and an MSS data system (MasCom, Bremen, Germany). The resolution of the instrument was set at 10,000 (100ppm peak width). Samples were mixed with m-nitrobenzyl-alcohol matrix deposited on the target of a direct insertion probe for introduction into the source. Nominal mass scan spectra were acquired with a mass scan range of 10-950 amu using a magnet scan rate of 25 sec/dec. For accurate mass measurements, a narrower mass scan range was employed, with the matrix containing 10% PEG mass calibrant”.

High Resolution EI and CI-MS (obtained using VG70S)

“High resolution EI and CI mass spectra were obtained using a VG70S double-focusing magnetic sector mass spectrometer (VG Analytical, Manchester, UK, now Micromass/Waters) equipped with an MSS data acquisition system (MasCom, Bremen, Germany). The resolution of the instrument was set at 10,000 (100ppm peak width). Samples were introduced into the source (block temperature = 200degC) using a heated direct insertion probe fitted with a deep quartz cup, with a heating rate of 0.5C/sec. Alternate EI and CI scans were acquired under control of the data system, with methane being used as the bath gas for the CI scans. The electron energy in both ionization modes was 70eV. Nominal mass scan spectra were acquired for a scan mass range of 10-900 amu using a magnet scan rate of 20 sec/dec. Accurate mass measurements were obtained across a narrower mass range using high boiling Perfluorokerosene (PFK) as the reference.”

Low Resolution EI-MS (obtained using Shimadzu QP5050A)

“Routine low resolution EI mass spectra were obtained using a Shimadzu QP5050A quadrupole based mass spectrometer (Shimadzu Instruments, Columbia, MD). Samples were introduced into the source using a quartz lined heated direct insertion probe with a heating rate of 10degC/min and a maximum heating temperature of 350degC. The electron energy was 70eV and the scan range was 45-600amu.”

GC-MS (obtained using Shimadzu GC17A/QP5050A)

“GC-MS analyses were performed using Shimadzu GC17A/QP5050A GC/MS combination (Shimadzu Instruments, Columbia, MD). The GC17A is equipped with a low polarity (5% phenyl-, 95%methyl-siloxane) capillary column (30m length, 0.25mm ID, 0.25um film thickness). Samples were dissolved in (specify solvent) at a concentration of Xmg/mL and injected into the instrument with an autosampler. The injector temperature was maintained at 250degC and the transfer interface at 280degC. The oven temperature was ramped from X degC to Y degC at a rate of Z degC/min. The QP5050A is an EI quadrupole based mass spectrometer with a maximum scan range of 900amu and an ionizing electron energy of 70eV. ”

ESI-MS (obtained using Finnigan LCQ)

“ESI mass spectra were acquired using a Finnigan LCQDeca ion-trap mass spectrometer equipped with an electrospray ionization source (Thermo Finnigan, San Jose, CA). Samples were dissolved in (specify solvent) with x% (specify modifier if you added one) and introduced into the instrument at a rate of 10uL/min using a syringe pump via a silica capillary line. The heated capillary temperature was 250 degC and the spray voltage was 5kV.”

Maldi-ToF

“Maldi-ToF mass spectra were obtained using a Kratos Kompact SEQ mass spectrometer (Manchester, UK). Samples were dissolved in (Specify solvent) and mixed with (specify matrix) before being deposited on the target plate. Samples were irradiated with a 337nm UV laser and mass analyzed by ToF mass spectrometry in the linear mode using a flight tube with a length of 1.7m.