Analysis of Pharmaceuticals and Personal Care Products in Groundwater by Online SPE and LC/MS/MS

Significance of the Topic

Environmental monitoring of trace pharmaceuticals and personal care products in groundwater is critical for assessing water quality and public health risks. Low concentration pollutants require sensitive, efficient analytical approaches to detect ng/L levels.

Study Objectives and Overview

This study aimed to develop and apply an automated online solid phase extraction (SPE) coupled with liquid chromatography-tandem mass spectrometry (LC/MS/MS) to identify and quantify seven target compounds in groundwater. Over 100 samples from alluvial wells in the South Platte River valley were analyzed to compare sampling techniques and evaluate method performance.

Methodology and Instrumentation

A 900 µL aliquot of filtered groundwater was preconcentrated on polymeric PLRP-S cartridges using the Agilent 1290 Infinity Flexible Cube system, followed by separation on an Agilent Poroshell 120 EC-C8 column and detection with an Agilent 6460 triple quadrupole MS. Sample draw, wash, and elution steps were fully automated with dual cartridges to minimize cycle time.

Main Results and Discussion

Recoveries for six analytes ranged from 86 to 164%, with method detection limits of 1–10 ng/L. Gabapentin showed lower recovery (34%) due to polarity issues. Analysis of well 009 detected all seven compounds, with sucralose at 3,360 ng/L and other analytes between 5 and 279 ng/L. Sampling variability (up to 100% concentration change) exceeded analytical variability (~10%), highlighting the impact of field collection.

Benefits and Practical Applications of the Method

Automated online SPE reduces solvent exposure, operator error, and analysis time (<20 min/sample) while requiring minimal sample volume (900 µL). The method supports high-throughput monitoring of trace contaminants in environmental water.

Future Trends and Applications

Integration of isotopically labeled surrogates for problematic analytes, exploration of alternative sorbents for polar compounds, and expansion to broader contaminant panels will enhance method robustness. Coupling with field-deployable sampling devices could facilitate real-time water quality assessment.

Conclusion

The automated online SPE–LC/MS/MS workflow delivers sensitive, rapid quantitation of pharmaceuticals and personal care products in groundwater using small sample volumes. It offers a cost-effective, reproducible solution for environmental monitoring programs.

References

No explicit literature cited; methodology and instrument specifications are based on manufacturer and standard practice.