Development and validation of a simple and robust LC-ESI single quadrupole MS-based method for cocaine detection in human urine.

PURPOSE: Advanced mass spectrometric platforms such as LC-MS/MS or quadrupole time-of-flight (QToF) are considered reliable for high-sensitivity detection of cocaine in human urine. However, these instruments are often not accessible to routine forensic laboratories due to financial and logistical constraints. The present study aims to develop and validate a cost-effective, rapid and environmentally suitable method using a single quadrupole-based LC-MS technique for the detection of cocaine in human urine. METHOD: The method employs an Acclaim C18 Column (150 × 3 mm, 5 μm) with a retention time (RT) of cocaine at 5.18 min within a total runtime of 8 min. An optimal chromatographic peak was achieved using 10 mM ammonium formate with 0.1% formic acid and acetonitrile with 0.1% formic acid, with a flow rate of 1000 µL/min and an injection volume of 5 µL.

RESULTS

The calibration demonstrated strong linearity (1–25 µg/ml; R² = 0.9959), with limit of detection (LOD) and limit of quantitation (LOQ) of 0.24 and 0.81 µg/ml, respectively. The method demonstrated excellent accuracy (105.8%) and precision (mean %RSD = 7.42%), along with 0% RSD in RT repeatability. Matrix effects (92.96%) and recovery (up to 71.23%) confirm suitability for forensic toxicology.

CONCLUSION

Research groups and forensic laboratories operating under budget constraints often depend on instrumentation with manageable resource requirements. The presented method for cocaine analysis provides a practical solution that does not require complex or high-end mass spectrometric systems.