Detection and Quantitation of Brominated and Chlorinated Hydrocarbons by DART with Linear Ion Trap and Triple Quadrupole Technology

Importance of the Topic

Persistent halogenated hydrocarbons such as brominated flame retardants (BFRs) and chlorinated pesticides (OCs) accumulate in ecosystems and pose health risks. Rapid, reliable screening and quantitation of these compounds are essential for environmental monitoring, regulatory compliance and public safety.

Objectives and Study Overview

This study aims to develop a direct, chromatography-free method for detecting and quantifying BFRs and OCs using ambient ionization coupled to high-performance mass spectrometry. Key goals include:

• Establishing ionization and fragmentation pathways for target analytes.
• Comparing performance of a linear ion trap versus a triple quadrupole instrument.
• Demonstrating sensitivity, reproducibility and applicability to real water samples.

Methodology and Instrumentation

Samples of 11 BFRs and one chlorinated reference (kepone) were prepared in acetone and spiked into water without cleanup. Two instruments were employed:

• Thermo Scientific LTQ linear ion trap MS with an IonSense DART-SVP source (200–270 °C, 300 V grid voltage) for full scan and MS/MS fingerprinting.
• Thermo Scientific TSQ Quantum Access MAX triple quadrupole MS with DART-SVP in direct infusion (400 °C grid) for selective reaction monitoring (SRM) and collision energy breakdown curves.

Main Results and Discussion

Ion trap experiments identified precursor ions and optimal MS/MS fragments for each analyte. Direct infusion on the TSQ confirmed these ions and allowed automatic tuning of tube lens voltages and collision energies. Fragmentation behavior differed between instruments due to the higher energy environment in the triple quadrupole. Calibration curves (0.01–1 mg/L) achieved linear responses for most compounds, with limits of detection down to 50 ppb. Analysis of a San Francisco tap-water sample showed no native analytes, while spiking at 500 ppb revealed variable matrix effects across compounds, underscoring the need for matrix-matched calibration or internal standards.

Benefits and Practical Applications

The DART-SVP direct-infusion approach eliminates chromatographic separation and extensive sample prep, reducing analysis time to minutes per sample. It provides both qualitative confirmation (full scan spectra matching theoretical isotopic patterns) and quantitative data via SRM. This workflow suits rapid screening in environmental labs, QA/QC settings and field-deployable platforms.

Future Trends and Potential Applications

Advances may include integration of stable-isotope-labeled standards to correct for spot-to-spot variability, expanded compound libraries covering emerging halogenated pollutants, and miniaturized or portable mass spectrometers for on-site monitoring. Machine-learning algorithms could automate spectral interpretation and improve throughput.

Conclusion

This study demonstrates that DART-SVP coupled with linear ion trap and triple quadrupole MS offers a fast, sensitive and robust method for detecting and quantifying BFRs and OCs in water. While matrix effects require careful calibration, the approach streamlines analysis by dispensing with conventional chromatography.

References

1. de Wit CA, Kierkegaard A, Ricklund N, Sellström U. Emerging Brominated Flame Retardants in the Environment. In: Eljarrat E, Barceló D, editors. Brominated Flame Retardants. Springer-Verlag Berlin Heidelberg; 2010.