Use of Non-Targeted Workflows for the Analysis of Pharmaceutical and Illicit Drug Occurrence in Environmental Samples

Significance of the Topic

Comprehensive monitoring of pharmaceuticals and illicit drugs in environmental waters is essential to evaluate human and ecological exposure to contaminants of emerging concern CECs. Non-targeted high resolution mass spectrometry workflows expand detection beyond predefined analytes enabling identification of novel or unexpected compounds in complex matrices.

Objectives and Study Overview

This study demonstrates combined targeted and non-targeted LC-MS/MS workflows to screen and quantify a broad range of pharmaceuticals and illicit drugs in wastewater and river water samples collected from an urbanized tidal river catchment in London UK. The goal is to enhance identification confidence and enable retrospective analysis of CECs.

Methodology and Instrumentation

Samples were filtered through 0.2 um PTFE membranes and directly injected into high resolution LC-MS/MS systems. The non-targeted workflow used a Shimadzu LCMS-9030 QTOF with data independent acquisition DIA MS/MS and Insight Analyze software for component deconvolution suspect screening and library matching. The targeted workflow employed a validated triple quadrupole LCMS-8060 in MRM mode for quantitation with authentic standards. Chromatography was performed on a Shim-pack Velox Biphenyl column with an ammonium formate formic acid mobile phase. Data processing was carried out in LabSolutions and Insight applications.

Main Results and Discussion

Non-targeted screening detected a range of compounds including metformin cocaine benzoylecgonine antidepressants and cutting agents such as levamisole. Targeted QTOF quantitation using authentic standards yielded concentration profiles in wastewater and river water which closely agreed with triple quadrupole results demonstrated by linear regression slope near unity and R2 above 0.92. The data independent approach permits retrospective addition of new analytes to the search list without reacquisition.

Benefits and Practical Applications

• Broad spectrum detection of known and emerging contaminants in a single analysis
• Retrospective screening potential supports longitudinal monitoring
• Enhanced confidence in compound identification via accurate mass isotopic patterns and library spectra
• Applicability to wastewater based epidemiology public health risk assessment and environmental compliance

Future Trends and Opportunities

Advances in crowd sourced and AI powered spectral libraries will further improve suspect screening workflows. Integration of machine learning for automated feature annotation and expansion to diverse environmental matrices will enhance throughput. Cloud based data sharing and standardized libraries will support collaborative monitoring of emerging contaminants.

Conclusion

The combination of non-targeted and targeted high resolution LC-MS/MS workflows provides a robust platform for comprehensive screening and quantitation of pharmaceuticals and illicit drugs in environmental samples. The DIA based approach ensures flexibility for future analytes while targeted quantitation delivers accurate concentration data.

Reference

1. KT Ng et al. J Hazardous Materials 398 2020 122933