Ultrasound-Assisted Liquid-Liquid Extraction for Analyzing Methadone in Urine Samples by Gas Chromatography-Mass Spectrometry

Background: methadone abuse and dependence are a growing concern in some countries. the present study developed and validated a rapid, simple, easy, and sensitive method for analyzing methadone in urine specimens. this approach was intended for use in clinical and forensic toxicology and drug screening laboratories. methods: we determined methadone in urine samples by gas chromatography / mass spectrometry (gc / ms). besides, we used ultrasound-assisted liquid-liquid extraction (ualle) method for the extraction and preconcentration of methadone before analysis. results: the detection limit was 2.1 ng/ml and the limit of quantification equaled 7 ng/ml. the methadone calibration curve was linear and ranged from 7 to 10000 ng/ml, and the correlation coefficient was calculated as 0.9984. the tested method was accurate and precise. recovery fell in the range of 81.3% to 97.4% and the enrichment factor was measured as 8.7. the method was successfully used for determining methadone in real clinical and postmortem urine samples. conclusion: the presented method was a rapid, easy, simple, and sensitive procedure; thus, it could be applied in clinical and forensic toxicology laboratories as a routine approach for analyzing methadone.