Using a Compact Single Quadrupole LC-MS for PFAS Analysis

Significance of the Topic

Per- and polyfluoroalkyl substances (PFAS) are persistent environmental pollutants of high concern due to their bioaccumulation and potential health risks.
Accurate detection and quantitation at trace levels are critical for environmental monitoring, remediation evaluation and regulatory compliance.
Compact analytical platforms that balance sensitivity, specificity and cost can broaden accessibility to PFAS analysis in routine laboratories.

Objectives and Study Overview

This study evaluates a compact single quadrupole LC-MS system (Shimadzu LCMS-2050) for the targeted analysis of 28 PFAS compounds.
Key aims include assessing linear dynamic range, limits of quantitation (LOQs), precision, and the feasibility of simultaneous selected ion monitoring (SIM) and scan acquisition for degradation product screening.

Methodology and Instrumentation

A Shimadzu Nexera UHPLC was coupled to an LCMS-2050 single quadrupole mass spectrometer.
A delay column (Shim-pack GIST C18, 5 µm, 3.0 × 50 mm) was used upstream to trap background PFAS.
Analytical separation employed a Shim-pack Velox C18 column (50 × 2.1 mm) with a 0.4 mL/min gradient of 5 mM ammonium acetate in water (A) and methanol (B) at 40 °C.
Injection volume was 1 µL into the DUIS source combining ESI and APCI.
Ion source conditions: nebulizing gas 2 L/min, drying gas 5 L/min, heating gas 7 L/min, DL temperature 200 °C, desolvation temperature 350 °C.
An acquisition method integrated a full scan (m/z 50–750) and SIM channels for each PFAS [M–H]– ion for quantitation.

Key Results and Discussion

All 28 PFAS targets were detected with linear calibration ranges spanning low-ng/mL to tens of ng/mL concentrations and correlation coefficients (R2) ≥ 0.994.
LOQs were defined at the lowest point in the linear range with signal-to-noise > 10, typically between 0.1 and 2 ng/mL depending on the analyte.
Accuracy of quantitation across the calibration range was between 80 % and 120 %, and %RSD at LOQ was below 12 % (n = 4).
The simultaneous scan event did not compromise SIM quantitation, enabling both targeted measurement and screening for unknown PFAS degradation products.

Benefits and Practical Applications of the Method

The compact single quadrupole configuration offers:

• Reduced maintenance and footprint compared to triple quadrupole systems
• Cost-effective operation for routine PFAS monitoring
• High sensitivity and reproducibility suitable for regulatory and research laboratories
• Capability to integrate screening for non-target PFAS alongside quantitation

The method supports environmental water testing, remediation performance assessment and evaluation of emerging PFAS treatment technologies.

Future Trends and Applications

Integration with automated sample preparation for high-throughput workflows.
Expansion of target panels to include ultra-short chain and novel fluorinated surfactants.
Hybrid approaches combining single quadrupole screening with high-resolution MS confirmation.
Deployment of compact LC-MS systems in field or mobile laboratories for on-site PFAS monitoring.

Conclusion

This work demonstrates that a compact single quadrupole LC-MS system can effectively separate and quantify a broad suite of PFAS at trace levels.
Its low maintenance, small laboratory footprint and dual acquisition capability make it a versatile tool for both routine and research-oriented PFAS analysis.