Pharmacists must find and measure genotoxic impurities (GTIs) in pharmaceutical products to protect patients. The objective of this study was to develop and validate an LC-MS/MS method for the sensitive and reliable detection of 5-Chloropyridine-2-amine, a potentially genotoxic impurity in the active pharmaceutical component etoricoxib, even at very low concentrations. Comprehensive validation was conducted on the approach's specificity, sensitivity, accuracy, and precision, and it achieved a limit of detection (LOD) and limit of quantification (LOQ) that were much lower than those of previously disclosed methods. To ensure compliance with regulatory requirements and safeguard pharmaceutical safety, it is highly recommended to conduct frequent quality control on Etoricoxib using this newly developed LC-MS/MS technique.