Determination of chlorpyrifos and its metabolites in cells and culture media by liquid chromatography-electro spray ionization tandem mass spectrometry (lc-ms/ms)

Abstract

A sensitive and specific method was developed for the simultaneous quantification of chlorpyrifos (CPF), its active metabolite chlorpyrifos oxon (CPO), and the detoxified product 3,5,6-trichloro-2-pyridinol (TCP). Sample preparation involved liquid-liquid extraction for culture media samples and protein precipitation for cell samples. Detection was performed using LC-MS/MS with multiple reaction monitoring (MRM) in positive ion mode for CPF and CPO, and selected ion recording (SIR) in negative ion mode for TCP. The method demonstrated linear ranges of 5–500 ng/mL for CPF, 0.2–20 ng/mL for CPO, and 20–2000 ng/mL for TCP in media samples, and 0.5–50 ng/million cells for CPF, 0.02–2 ng/million cells for CPO, and 2–200 ng/million cells for TCP in cell samples. The method was fully validated for selectivity, linearity, precision, accuracy, recovery, stability, and dilution integrity. It has been successfully applied to investigate the neurotoxicity and metabolism of chlorpyrifos in a human neuronal cell model.

Keywords: Chlorpyrifos, Chlorpyrifos Oxon, TCP, Neuron, Metabolism, Neurotoxicity, Culture Media, LC-MS/MS