Agilent 7890B Gas Chromatograph (GC) with an Agilent 7250 Quadrupole-Time-of-Flight (Q-TOF) with a Gerstel MultiPurpose Sampler (MPS) and Gerstel Thermal Desorption System (TDS3) with a Gerstel Autosampler (TDSA2)

The Agilent 7250 Series accurate mass Q-TOF is a stand-alone Q-TOF mass spectrometer coupled to an Agilent 7890B Series gas chromatograph. The instrument utilizes electron ionization (EI) at either 15V or 70V at this time. A Grestel multipurpose sampler (MPS Robotic Pro) with tool changer is attached to allow robotic sample preparation and headspace sample analyses. The Gerstel thermal desporption system (TDS3) enables the analysis of volatile and semi-volatile organics using a Gerstel TDSA2 autosampler.

Agilent 7890B Gas Chromatograph Specifications:

  • Full electronic pressure control
  • Split/splitless injector on front 40 ˚C – 450 ˚C
  • Gerstel CIS-4 programmable temperature vaporizer on back
    • Liquid N2 cooled, low thermal mass -150 ˚C – 450 ˚C (heat up to 12 ˚C/sec)
    • 1.8 mm i.d. liners with variety of packings for purge/trap
  • Usually 0.18 mm i.d., 20 m DB-5MS column on back, 0.25 mm i.d., 30 m DB-5MS column on front
  • 150 position autosampler for 0.1-5 uL injections


Agilent 7250 Q-TOF Specifications:

  • Mass range: 15-1200 Da (normal) or 100-3000 Da for (extended)
  • Mass accuracy: < 3 ppm, resolving power: 25,000
  • Extractor Low energy EI source (EI voltage tuned @ 15 eV and 70 eV)
    • 15 eV EI and 180 ˚C source increases yield of molecular ion
  • Tandem MS using N2 as collision gas, 0-100 V collision energy
    • Quadrupole precursor isolation (0.6 Da wide window min.)


Gerstel MPS Specifications:

  • Tray holds 3 sample racks (54×1.5 mL vials or 15×20 mL vials)
  • 3 position tool changer with many syringes available
    • Typically 10 µL liquid syringe, 50 µL liuqid syringe, and 2.5 mL heated/purged headspace syringe mounted
    • Permits separate reagent addition and GC sampling syringes to be used in same method (e.g. Add TMS derivatization reagents with 50 µL syringe prior to sampling with 10 µL syringe for GC-MS analysis after reaction completes)
  • Heated agitator for chemical reactions or headspace sample prep
    • Max speed 750 rpm, max temp 150 ˚C
  • Sample prep and GC-MS analysis steps can be decoupled to maximize instrument utilization and ensure all samples have similar hold times after a reaction


Gerstel TDS Specifications:

  • 20 position autosampler thermal desorber
    • Compatible with Twister SBSE (dimethylsiloxane and ethylene glycol stationary phases)
    • Can use 6mm x 4mm, 7“ tubes packed with other sorbents (Tenax, Carbotrap, etc.)
    • Desorber temperature range -50 ˚C – 400 ˚C
    • Use with CIS-4 for purge and trap sampling
  • CIS-4 cooled inlet sytem (programmable temperature desorber)
    • Liquid N2 cooled, low thermal mass -150 ˚C – 450 ˚C (heat up to 12 ˚C/sec)
    • 8 mm i.d. liners with variety of packings for purge/trap


Popular Assays:

  • Formula confirmation by accurate MS
  • Untargeted metabolomics after derivatization
  • Complex mixture GC/MS using accurate MS
  • Stable isotope label fluxomics


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