Multi-component quantitative analysis of pharmaceuticals and personal care products in the environment by LC-MS/MS with fast polarity switching

Significance of the Topic

The widespread release of pharmaceuticals and personal care products (PPCPs) into aquatic environments poses risks due to their persistence, bioactivity and endocrine-disrupting potential. Developing rapid, sensitive and multi-residue analytical methods is essential for environmental monitoring, regulatory compliance and risk assessment.

Study Objectives and Overview

This work aimed to establish a unified UHPLC-ESI-QqQ method capable of quantifying diverse PPCP classes in surface waters. The key goals were to:

• Implement fast polarity switching to detect both positively and negatively ionizing analytes in a single run.
• Optimize the chromatographic gradient to minimize matrix effects and achieve ng/L detection limits.
• Compare performance against conventional single-polarity analyses and evaluate long-term stability.

Methodology and Used Instrumentation

Surface water samples from Japanese rivers and lakes were spiked with 15 PPCPs at concentrations ranging from 1 to 10 000 ng/L without pretreatment.

Used Instrumentation

• UHPLC System: Nexera (Shimadzu, Japan)
• Column: Shim-pack XR-ODSIII (2.0 mm × 50 mm, 1.6 µm) at 40 °C
• Mobile Phases: A – 0.1% formic acid in water; B – acetonitrile; 21 min gradient (0→80% B in 16 min; 100% B at 18 min; re-equilibration to 0% B by 21 min); flow 0.4 mL/min; injection 40 µL
• MS Detector: LCMS-8080 triple quadrupole (Shimadzu, Japan) with ESI, fast polarity switching (20 ms)
• Gas and Temperature Settings: nebulizing 3.0 L/min; curtain 3.5 L/min; heating 12.0 L/min; probe 450 °C; HSID 300 °C

Main Results and Discussion

Optimized gradient separation effectively focused analytes at early elution and reduced matrix interferences.
All 15 PPCPs showed excellent linearity (R2 > 0.999) and limits of quantification between 1 and 50 ng/L. Recoveries in river and lake water ranged from 70% to 120%.

Fast polarity switching delivered data quality comparable to dedicated positive- or negative-only runs. Over 100 sequential injections (10 h), %RSD for representative compounds remained below 4%, demonstrating high stability and reproducibility.

Benefits and Practical Applications

This single-run, multi-residue approach reduces analysis time, solvent use and instrument workload. Achieving sub-ppb sensitivity for a diverse compound set makes it suitable for routine environmental monitoring, water quality assessment and regulatory screening.

Future Trends and Potential Applications

Advances may include coupling to high-resolution MS for suspect screening, automated on-site sampling, broader analyte libraries and integration with data-driven risk models. Further miniaturization and real-time analysis could enhance field deployability and rapid response capabilities.

Conclusion

The UHPLC-ESI-QqQ method with fast polarity switching provides a robust, sensitive and efficient solution for multi-component quantification of PPCPs in environmental waters. Its high reproducibility and low detection limits support comprehensive monitoring and safeguard ecosystem and human health.