LC/HRMS, LC/MS, LC/MS/MS, LC/Orbitrap
IndustriesManufacturerThermo Fisher Scientific
Importance of the Topic
The ability to perform high-resolution accurate-mass (HRAM) liquid chromatography–tandem mass spectrometry (LC-MS/MS) is essential across diverse fields such as environmental monitoring, food safety, clinical research, and pharmaceutical analysis. Instruments that combine rapid scan speeds, sub-ppm mass accuracy, broad dynamic range, and versatile acquisition modes enable both targeted quantitation and comprehensive screening in a single workflow.
Objectives and Study Overview
This summary presents the key specifications and performance characteristics of the Thermo Scientific Q Exactive Focus Orbitrap LC-MS/MS system. The goal is to highlight its analytical capabilities, operating modes, and practical considerations for routine laboratory use in small-molecule identification, quantitation, and untargeted screening.
Methodology and Used Instrumentation
The Q Exactive Focus integrates a quadrupole precursor selector with an HRAM Orbitrap analyzer. Key components include:
- Ion Source: H-ESI II with dual desolvation zones, sweep gas and 60° interchangeable probe orientation.
- Ion Optics: Stacked-ring RF lens and bent flatapole for efficient ion focusing and noise reduction.
- Quadrupole Filter: HyperQuad mass filter offering isolation widths from 0.4 Da to full mass range.
- HCD Collision Cell and C-Trap: Nitrogen-filled trap and straight multipole cell for higher-energy collisional dissociation.
- Orbitrap Analyzer: 5 kV central electrode, low-noise preamplifier and 16-bit digitization achieve up to 70,000 resolving power at m/z 200.
- Vacuum System: Differentially pumped stages with turbomolecular and rotary vane pumps delivering <1 × 10⁻⁹ mbar.
- Data Acquisition and Software: Real-time control, automatic gain control (AGC), Thermo Scientific Xcalibur and TraceFinder software.
Acquisition modes supported:
- Full MS (high-resolution accurate mass)
- Selected Ion Monitoring (SIM)
- Parallel Reaction Monitoring (PRM)
- Data-Independent Acquisition (DIA/vDIA)*
- All-Ion Fragmentation (AIF)
*vDIA not available in the United States.
Main Results and Discussion
The system achieves scan speeds up to 12 Hz and maintains mass accuracy below 1 ppm (internal calibration) with linear dynamic range exceeding six orders of magnitude. Sensitivity tests report 500 fg buspirone on-column (S/N 100:1) in full MS and 50 fg in SIM. Polarity switching between positive and negative modes completes in under one second, maximizing compound coverage. These performance metrics support fast, reproducible screening and quantitation workflows.
Benefits and Practical Applications
The compact benchtop design, ease of maintenance and integrated software make the Q Exactive Focus well suited for:
- Food safety residue testing
- Environmental contaminant monitoring
- Forensic toxicology and sports doping analysis
- Clinical bioanalysis and metabolomics
- Pharmaceutical R&D and quality control
Its combination of targeted quantitation (PRM, SIM) and untargeted screening (DIA, AIF) streamlines laboratory workflows and reduces the need for multiple instruments.
Future Trends and Potential Applications
Advances in HRAM mass spectrometry will focus on deeper integration of data-independent methods, real-time decision-making, and machine-learning–assisted spectral interpretation. The expansion of ambient ionization interfaces and microflow chromatography is expected to further extend applications in clinical diagnostics, on-site environmental monitoring, and rapid process analytical technology.
Conclusion
The Thermo Scientific Q Exactive Focus Orbitrap LC-MS/MS platform delivers high throughput, sub-ppm mass accuracy, broad dynamic range, and versatile acquisition modes in a robust benchtop system. Its performance and flexibility address the evolving needs of routine analytical laboratories across multiple disciplines.
Content was automatically generated from an orignal PDF document using AI and may contain inaccuracies.