An integrated LC-MS/MS workflow for multi-matrix determination of glyphosate and aminomethylphosphonic acid for occupational exposure assessment.

Glyphosate, a widely used herbicide in agricultural and forestry settings, raises significant concerns regarding potential occupational exposure. However, comprehensive exposure assessment integrating biological and environmental monitoring remains limited, partly due to the lack of analytical workflows capable of supporting multiple sample matrices on a single platform. Here, we developed and validated a high-throughput derivatization-free LC-MS/MS workflow for the determination of glyphosate and aminomethylphosphonic acid (AMPA) in urine, surface wipes, patches and breath zone air monitoring samples collected using Occupational Safety and Health Administration (OSHA) versatile sampler (OVS) tubes. The workflow combines selective solid-phase extraction (SPE) using AFFINIMIP molecularly imprinted polymer cartridges for urine with a simplified universal aqueous extraction workflow for environmental matrices, enabling efficient analysis of diverse matrices using a single analytical platform. Chromatographic separation was achieved on a mixed-mode Obelisc N column within 6 minutes, with the in-sample addition of 0.1 mmol L-1 methylenediphosphonic acid (MA) significantly improved peak shape and sensitivity. The method demonstrated excellent specificity, accuracy and precision across all matrices. The limits of detection (LODs) for glyphosate and AMPA were 0.1 and 0.2 ng mL-1 in urine, respectively; and 1.6 ng in surface wipes and patches, and 0.4 ng in OVS air samples for both analytes. The method was successfully applied to 1121 biological and environmental samples collected from forestry workers in Australia, confirming its suitability for real-world exposure assessment. By integrating biomonitoring and environmental monitoring within a single analytical platform, this approach provides a practical and high-throughput tool for comprehensive assessment of occupational glyphosate exposure.