A fast, robust method for routine determination of polycyclic aromatic hydrocarbons (PAH) in drinking water by single quadrupole GC-MS

Importance of the Topic

Polycyclic aromatic hydrocarbons (PAHs) are toxic organic pollutants arising from incomplete combustion of fossil fuels and biomass. Due to their carcinogenic and endocrine‐disrupting properties, regulatory bodies worldwide set stringent limits for PAHs in drinking water. Routine, sensitive, and high‐throughput analytical methods are essential to ensure compliance and protect public health.

Objectives and Study Overview

This application note evaluates a fast and robust workflow for the simultaneous determination of 41 PAHs in drinking water. The study demonstrates the performance of a Thermo Scientific™ ISQ™ 7000 single quadrupole GC‐MS, coupled with a TRACE™ 1310 gas chromatograph and AI/AS 1310 autosampler, using a TraceGOLD™ TG‐PAH column and optimized SIM acquisition.

Methodology and Instrumentation

Water samples (1 L) were spiked with deuterated internal standards and extracted by reversed‐phase solid‐phase extraction (SPE). Eluates were concentrated and reconstituted in ethyl acetate. The GC separation employed a 60 m × 0.25 mm × 0.10 µm TraceGOLD TG‐PAH column with a temperature program reaching 350 °C in under 30 minutes. Detection used electron ionization (70 eV) in selected ion monitoring (SIM) mode for target and qualifier ions.

Instrumental Setup

• Gas chromatograph: Thermo Scientific TRACE 1310 GC with SSL inlet (splitless).
• Column: TraceGOLD TG‐PAH, 60 m × 0.25 mm × 0.10 µm.
• Mass spectrometer: Thermo Scientific ISQ 7000 single quadrupole with ExtractaBrite source.
• Autosampler: Thermo Scientific AI/AS 1310 liquid autosampler.
• Software: Chromeleon CDS 7.2 for automated control, processing, and reporting.

Main Results and Discussion

• Chromatographic resolution (Rs ≥ 1.0) achieved for all PAH isomers, with complete elution in less than 30 minutes. Critical pairs were resolved by mass discrimination.
• Linearity assessed over six levels (2–1000 ng/mL) yielded R² > 0.9980 and average calibration factor RSDs < 15%.
• Instrument detection limits ranged from 0.3 to 0.9 pg on‐column for individual PAHs.
• Repeatability tests (n=14) showed peak area RSDs < 4% (max 5.7%), highlighting autosampler and ion source ruggedness.
• Matrix‐spike recoveries in drinking water (n=6) deviated < 13% at low (10–100 ng/mL) and < 6% at high (100–1000 ng/mL) levels.
• System stability over 100+ sample injections (three days, no maintenance) maintained QC RSDs < 10% for all PAHs.

Benefits and Practical Applications

• High throughput: <30 min run time for 41 PAHs.
• Robustness: consistent performance over extended batch runs without maintenance.
• Sensitivity: low detection limits meet regulatory requirements.
• Cost‐effectiveness: single quadrupole GC‐MS platform with automated workflows.

Future Trends and Possibilities

Integration of automated SPE, expanded SIM libraries for emerging PAHs, and coupling with high‐resolution mass spectrometry could further enhance selectivity and coverage. Application of multiplexed sampling and data analytics will support real‐time monitoring and large‐scale water quality assessments.

Conclusion

The demonstrated GC‐MS method offers rapid, sensitive, and reliable quantitation of 41 PAHs in drinking water. Its high resolution, reproducibility, and minimal maintenance make it suitable for routine environmental monitoring and regulatory compliance.

References

• Liu L.-B. et al., J. Environ. Sci. 2007,19(1),1–11.
• Cavalieri E. et al., Carcinogenesis 1978, 3,273–287.
• Duedahl-Olesen L., in Persistent Organic Pollutants, Woodhead 2013,308–333.
• Zelinkova Z.; Wenzl T., Polycyclic Aromat. Compd. 2015,35(2–4),248–284.
• Wenzl T. et al., Trends Anal. Chem. 2006,25,716–725.
• Directive 2000/60/EC and Decision 2455/2001/EC, EU Water Framework Directive.
• Skoczynska E.; de Boer J., Retention 2019,6(7),8–12.
• Thermo Fisher Chromeleon CDS 7.2, BR72617-EN0718S.
• Ottaviani M.; Bonadonna L., Rapporti ISTISAN 07/31 (2007).
• US EPA Method 525.3, 1995.
• European Pharmacopoeia 9.0, General chapter <2.2.46>, 2016.
• USP <621> Chromatography, USP 40-NF 35 Supplement (2017).
• Law R.; Albertini T., TN 10499, Thermo Fisher (2018).
• Thermo Fisher ISQ 7000 System, BR10588 (2019).