Retrospective Biomarker-Based Identification of Propoxur and Related Carbamates Using Advanced Mass Spectrometry and Biosensing Platforms
Ranu Chaturvedi *
P K University, Thanra, Shivpuri (MP), India.
Vikash Verma
Department of Chemistry, Faculty of Science, P K University, Thanra, Shivpuri (MP), India.
*Author to whom correspondence should be addressed.
Abstract
This work describes a unique, dual-platform analytical methodology for the retrospective identification and quantification of Propoxur (2-Isopropoxyphenylmethylcarbamate) and other related N-methyl carbamates based on their specific protein-adduct biomarkers rather than the parent compounds. Carbamates are potent inhibitors of acetyl cholinesterase (AChE) forming a transient, carbamylated enzyme complex. We will exploit residual, slowly hydrolyzing carbamoylated protein adducts in biological matrices, particularly in erythrocyte acetyl cholinesterase (RBC-AChE), as stable, long-term exposure biomarkers. The approach pairs a high-resolution, high-sensitivity Ultra-High Performance Liquid Chromatography-Tandem Mass Spectrometry (UHPLC-MS/MS) platform for confirmatory analysis of released carbamic acids/phenolic metabolites with an Enzymatic Electrochemical Biosensing Platform (EEBP) for rapid, on-site screening of residual AChE inhibition. It significantly expands the time window for the temporal assessment of exposure, thus providing unequivocal retrospective evidence of carbamate poisoning beyond the very short and rapid detoxification phase.
Keywords: Propoxur, carbamate biomarkers, acetyl cholinesterase (AChE) inhibition, protein adducts, UHPLC–MS/MS, electrochemical biosensor, retrospective exposure, toxicological forensics