Thermo Scientific ISQ EC and ISQ EM single quadrupole mass spectrometers

Importance of the topic

Mass spectrometry (MS) is a cornerstone technique in modern analytical chemistry, providing unmatched sensitivity and selectivity for the detection and identification of compounds in complex sample matrices. Integrating MS with ion chromatography (IC) and liquid chromatography (LC) transforms routine analyses into powerful workflows that reduce false positives/negatives and deliver structural confirmation.

Objectives and overview of the study

This whitepaper presents the Thermo Scientific™ ISQ™ EC and ISQ™ EM single quadrupole mass spectrometers, engineered for robustness, ease of use, and seamless coupling to IC and LC systems. The goal is to demonstrate how these instruments simplify sample-to-knowledge journeys for both novice and expert users.

Methodology and instrumentation

The ISQ EC model targets low-molecular-weight ions (m/z 10–1250) with a heated electrospray ionization (HESI) source. The ISQ EM extends the mass range (m/z 10–2000) and adds atmospheric pressure chemical ionization (APCI) for non-polar analytes. Both instruments feature an orthogonal ion source for prolonged uptime, integrated control through Chromeleon™ CDS software, and guided Easy and Advanced modes for rapid method development.

Main results and discussion

Performance highlights include:

• Reserpine peak area reproducibility with total RSD ≈ 4% over multiple days and interface maintenance
• Single-digit ppb detection limits for perchlorate via IC-MS without organic solvent make-up
• Resolution of co-eluting anions (succinate m/z 117 and malate m/z 133) in SIM mode
• Parallel full-scan and SIM impurity profiling in pharmaceutical LC-MS workflows, capturing trace levels of known and unknown peaks
• Extended mass range enabling detection of multiple charge states for peptides and oligonucleotides, e.g., LL-37 peptide charge states +3 to +8

These results underline the instruments’ ability to deliver sensitive, selective, and reproducible data in routine and challenging applications.

Benefits and practical applications

The ISQ EC and ISQ EM systems offer:

• Robust day-to-day performance with minimal downtime
• Enhanced selectivity via mass-based peak confirmation
• Flexible ionization (HESI and APCI) for polar and non-polar compounds
• Integrated software tools for automated tuning, embedded method guidance, and regulatory compliance

They are ideally suited for environmental monitoring, pharmaceutical impurity analysis, biopharmaceutical characterization, and quality control in regulated laboratories.

Future trends and opportunities

Further automation of MS workflows, integration with cloud-based data analytics, and incorporation of machine learning algorithms will drive broader adoption of single quadrupole MS. Emerging applications in on-site and high-throughput screening are expected to benefit from compact, user-friendly designs.

Conclusion

The Thermo Scientific ISQ EC and ISQ EM single quadrupole mass spectrometers provide a balanced solution of simplicity, robustness, and performance. By seamlessly integrating with IC and LC systems and offering guided software workflows, they accelerate routine analyses and expand the reach of MS across diverse laboratory environments.

Used instrumentation

• Thermo Scientific ISQ EC Single Quadrupole Mass Spectrometer
• Thermo Scientific ISQ EM Single Quadrupole Mass Spectrometer
• Thermo Scientific Dionex ICS-6000 and Integrion HPIC Systems
• Thermo Scientific Vanquish UHPLC Systems
• Thermo Scientific Chromeleon Chromatography Data System