Surface water screening for chloroalkane contamination via Bruker μDROP and GC-MS/MS

Significance of the Topic

Short-chain chlorinated paraffins (SCCPs) are persistent, bioaccumulative, and toxic pollutants previously used in plastics, sealants, coatings, and metal-working lubricants. Regulatory bodies classify SCCPs as priority hazardous substances due to ecological harm and human health risks. Surface waters are particularly vulnerable to SCCP contamination via plastic recycling, leaching, and wastewater effluent. Meeting stringent EU Environmental Quality Standards (annual average <400 ppt, maximum allowable concentration <1400 ppt, method LOD ≤120 ppt) requires sensitive, reliable, and high-throughput analytical solutions.

Aims and Overview of the Study

This work evaluates the combination of Bruker µDROP dispersive liquid–liquid microextraction and the EVOQ GC-Triple Quadrupole MS/MS system for rapid, sensitive, and specific detection of short-chain chloroalkanes (C10–C13) in diverse surface water matrices. Key objectives include method linearity, sensitivity (MDL/MRL), specificity against co-extracted semi-volatile organic compounds, and compliance with current EU directives.

Methodology

• Sample Preparation: 35 mL water spiked with SCCP standard and PCB 30 internal standard was subjected to µDROP extraction: mixing with ready-to-use extraction solvents, room-temperature centrifugation (3000 rpm, 10 min), and droplet collection.
• Calibration: Water matrices (ultrapure, tap, river, sea) were spiked at 50–1000 ppt SCCPs, with PCB 30 at 500 ppt. Four replicates per level assessed linearity and precision.
• Sensitivity Testing: Method Reporting Limit (MRL) defined at 50 ppt; Method Detection Limit (MDL) determined at 25 ppt (S/N >10 for quantitation and confirmation ions).
• Specificity Assessment: Low-level SCCP samples (50 ppt) were co-spiked with a 100+ pesticide mixture at 1000 ppt to evaluate potential interferences.

Instrumentation Used

• Extraction: Bruker µDROP kit (dispersive liquid–liquid microextraction).
• Gas Chromatography: Bruker 436 GC with 1079 inert PTV injector and BR-5ms column (30 m × 0.25 mm, 0.25 µm film).
• Mass Spectrometry: Bruker EVOQ GC-TQ MS/MS, electron ionization at 70 eV, MRM mode with argon collision gas, data processed in Bruker Compass TQ software.

Main Results and Discussion

• Linearity and Precision: Calibration curves in all matrices achieved R² >0.99 and RSD between 9 % and 15 %.
• Sensitivity: MDL of 25 ppt and MRL of 50 ppt both outperform the regulatory requirement of 120 ppt.
• Specificity: No impact from co-extracted pesticide SVOCs; the same µDROP extract can be injected under alternative GC conditions to analyze other pollutant classes.

These results demonstrate the robustness of µDROP enrichment coupled with EI-MS/MS, delivering rapid (≈11 min prep), eco-friendly, and high-throughput analysis with minimal solvent and waste generation.

Benefits and Practical Applications

• Consistent quantitation independent of carbon chain length or chlorination degree.
• High enrichment factors (up to 1000×) and recoveries (70–120 %) enable trace-level detection.
• Compliance with EU surface water regulations (EQS, LOD/LOQ criteria).
• Streamlined workflow adaptable to environmental monitoring, QA/QC labs, wastewater screening, and soil-leachate analysis.

Future Trends and Potential Applications

Integration of microextraction methods with advanced MS technologies will expand multi-residue screening for diverse pollutant classes. Automation and on-site portable systems may enable real-time monitoring. Further miniaturization and solvent-saving innovations will strengthen alignment with green analytical chemistry principles. Combining high-resolution data analytics and machine learning could enhance detection specificity and workflow efficiency.

Conclusion

The combined Bruker µDROP and EVOQ GC-TQ MS/MS workflow offers a precise, sensitive, and rapid approach for monitoring short-chain chloroalkane contamination in surface waters. Exceeding EU regulatory performance criteria, this method extends green chemistry benefits to the laboratory and supports broad applications in environmental analysis.

References

1. Regulation 2019/1021/EU on persistent organic pollutants.
2. Directive 2013/39/EU on priority substances in water policy.
3. van Mourik LM, Leonards PEG, Gaus C, de Boer J (2015). Recent developments in capabilities for analysing chlorinated paraffins in environmental matrices: a review. Chemosphere 136:259–272.
4. Zencak Z, Reth M, Oehme M (2004). Determination of total polychlorinated n-alkane concentration in biota by electron ionization–MS/MS. Anal Chem 76:1957–1962.
5. Bruker Application Note LCMS-136: Determination of SVOCs in water using µDROP and EVOQ GC-TQ MS/MS.
6. Bruker Application Note GCMS-13: Rapid multiresidue pesticide determination in wine using µDROP and GC-MS/MS.