Towards Single System for Total Water Analysis. LC-MS/MS screening of 325 PPCP Contaminants in Tap and Surface Water

Significance of the Topic

The widespread entry of pharmaceuticals and personal care products (PPCPs) into drinking and surface water has raised environmental and public health concerns. Trace-level monitoring is critical to assess human exposure and ecological impact. Developing a comprehensive, automated LC-MS/MS workflow capable of detecting hundreds of PPCPs at sub-ppt levels addresses the need for high throughput, sensitivity, and adaptability in routine water quality surveillance.

Objectives and Study Overview

This work aimed to implement a single analytical platform that automatically switches between methods to screen 325 PPCP targets in tap and surface water samples. Key goals included achieving low limits of quantification (LLOQs) across diverse chemical classes, maximizing compound coverage, and demonstrating robustness in complex matrices using minimal manual intervention.

Methodology and Instrumentation

The workflow combined four analytical methods differentiated by mobile phase pH (acidic and basic) and sample introduction mode (direct injection and online solid-phase extraction). A Nexera X2 UHPLC system was coupled to an LCMS-8060 triple quadrupole with the following components:

• Direct injection: 150 µL volume, 22-minute run time.
• Online SPE: 1500 µL load, 28-minute run time, using Evolute Express ABN cartridges.
• Acidic mobile phase: water/methanol with 0.1% acetic acid and ammonium fluoride, using Shim-pack Velox Biphenyl columns.
• Basic mobile phase: water/acetonitrile with ammonium hydroxide, using Shim-pack Scepter HD-C18 columns.

Compounds were divided into multiplexed groups of ~100 per injection, and nine internal standards were distributed across the chromatogram to support quantitation. A ten-point calibration (0.1–100 ppt) with five replicates per level ensured linearity and accuracy without manual processing, using LabSolutions Insight software.

Main Results and Discussion

Of 325 targets, 304 were confirmed and quantified. In tap water, 89% of compounds achieved LLOQs ≤30 ppt and 71% reached ≤1 ppt. Surface water yielded 85% ≤30 ppt and 61% ≤1 ppt despite greater matrix complexity. The most comprehensive single method (acidic direct injection) provided 86% overall coverage and 80% ≤30 ppt. Incorporating additional methods (online SPE and basic pH) enhanced the number of compounds with LLOQs below 30 ppt by up to 5% and improved total coverage by a similar margin, illustrating the benefit of a flexible multi-method scheme.

Benefits and Practical Application

The proposed system delivers:

• Broad chemical coverage for routine tap and surface water testing.
• Sub-ppt sensitivity for early warning and regulatory compliance.
• Automated method switching to balance throughput and depth of screening.
• Reduced manual intervention and simplified data processing.

These features make it suitable for environmental monitoring programs, water utilities, and research laboratories requiring high-volume, high-sensitivity PPCP profiling.

Future Trends and Potential Applications

Further development may include integration of high-resolution mass spectrometry for non-target screening, expanded compound libraries covering emerging contaminants, and real-time data analytics for smart monitoring networks. Miniaturized or field-deployable LC-MS/MS platforms could extend this approach to on-site water quality checks in remote locations.

Conclusion

This study demonstrates a robust, automated LC-MS/MS platform capable of comprehensive PPCP screening in tap and surface water at trace levels. The multi-method configuration achieves high sensitivity and coverage while offering flexibility to adapt to regulatory and research needs, marking a significant advance toward total water analysis.

Used Instrumentation

• Shimadzu Nexera X2 UHPLC
• Shimadzu LCMS-8060 triple quadrupole
• Shim-pack Velox Biphenyl and Shim-pack Scepter HD-C18 columns
• Evolute Express ABN SPE cartridges

References

No external literature references were provided in the source text.