Development of GC/TQ Methods for the Analysis of Hazardous Chemicals

Importance of the Topic

The accurate detection and quantitation of hazardous substances of very high concern (SVHCs) regulated under the European REACH legislation is critical for product safety and regulatory compliance. Gas chromatography coupled with triple quadrupole mass spectrometry (GC/TQ) in multiple reaction monitoring (MRM) mode offers high selectivity and sensitivity for complex chemical mixtures, reducing interferences from coeluting matrix components.

Objectives and Study Overview

This study aimed to streamline the development of MRM methods for 170 target compounds, including phthalates, industrial chemicals, flame retardants, aryl amines, siloxanes and polycyclic aromatic hydrocarbons (PAHs), following additions to the SVHC candidate list. Two approaches were compared: a conventional manual method for 100 compounds and an automated workflow using Agilent MassHunter Optimizer for GC/TQ to generate MRM transitions for 70 additional analytes.

Methodology

Sample Preparation and Calibration

• Polymer samples were cut and extracted with hexane:acetone (1:1) at 50 °C for 1 h.
• Calibration standards were prepared in solvent at 0.1–10 µg/mL for external calibration.

Automated MRM Development Workflow

• Full-scan acquisition to detect precursor ions by spectral deconvolution.
• Product ion scans at multiple collision energies (e.g. 0–60 eV) to identify fragment ions.
• Collision energy optimization for each transition via ion breakdown plots.
• MRM transitions saved as dynamic MRM (dMRM) methods or exported to a database.

Used Instrumentation

Agilent 8890 GC with a 7693A autosampler and multimode inlet (MMI)
Agilent 7000D triple quadrupole MS operated in electron impact mode at 70 eV
J&W HP-5ms Ultra Inert capillary column (30 m × 0.25 mm, 0.25 µm) with post-column backflush via a purged Ultimate union
Helium carrier gas (1.2 mL/min constant flow), nitrogen collision gas (1.5 mL/min), helium quench gas (2.25 mL/min)

Main Results and Discussion

The automated workflow generated optimized MRM transitions for 70 compounds in under 24 h (including 41 chromatographic runs) versus more than one week by conventional methods. Calibration curves for all analytes showed linearity with R2 > 0.97 over 0.1–10 mg/L. A dynamic MRM method covering 170 compounds was applied to polymer extracts, enabling accurate quantitation of phthalates, siloxanes, phenolic compounds and other SVHCs at trace levels. The selectivity of MRM transitions minimized matrix interferences.

Benefits and Practical Applications

Use of the MassHunter Optimizer for GC/TQ:

• Reduces method development time from days to hours.
• Eliminates complex time-segment scheduling by employing dynamic MRM acquisition.
• Enhances quantitative precision and expands linear dynamic range.
• Simplifies updating methods when new SVHCs are added to REACH candidate lists.

Applied in QA/QC and environmental monitoring laboratories, this approach improves throughput and ensures regulatory compliance.

Future Trends and Opportunities

Automated MRM development is expected to integrate with laboratory information management systems (LIMS) and cloud-based spectral libraries. Extensions to other workflows such as LC–MS/MS and incorporation of machine learning for peak detection and transition selection promise further gains in speed and robustness. Dynamic scheduling algorithms will continue to optimize duty cycle and sensitivity for ever-growing compound lists.

Conclusion

The Agilent MassHunter Optimizer for GC/TQ dramatically accelerates MRM method development for regulatory and industrial analysis of SVHCs. By automating precursor and fragment ion selection, collision energy optimization and method assembly, the workflow reduces hands-on time, enhances sensitivity and facilitates rapid response to evolving chemical regulations.

References

1. ECHA. Implementation of REACH and CLP Regulations. European Chemicals Agency, https://www.echa.europa.eu/web/guest/regulations/reach/understanding-reach
2. Forum Methodology for Recommending Analytical Methods to Check Compliance with REACH Annex XVII Restrictions, European Chemicals Agency.
3. Andrianova A, Quimby B, Churley M. Automated MRM Method Development for US EPA Method 8270 with the Agilent MassHunter Optimizer for GC/TQ. Agilent Technologies Application Note 5994-2086EN, 2020.