Ultrasound-assisted liquid-liquid extraction for the determination of methadone in urine samples using gas chromatography-mass spectrometry

Abstract

Background: Methadone abuse and dependence has been reported as a growing concern in some countries. In present study, a rapid, simple, easy and sensitive method for determination of methadone in human urine samples for use in clinical and forensic toxicology and drug screening laboratories was developed and validated.
 Methods: We determined methadone in urine sampled by gas chromatography/mass spectrometry (GC/MS) and used ultrasound assisted liquid-liquid extraction (UALLE) method for the extraction and preconcentration of methadone before analysis.
 Results: The limit of detection was 2.1 ng/mL and the limit of quantification 7 ng/mL. Correlation coefficient was 0.9984 for the methadone calibration curve in linear range from 7 to 10,000 ng/mL. The method is accurate and precise. Recovery was in the range of 81.3 % to 97.4 % and enrichment factor was 8.7. The method was successfully applied for determining methadone in clinical and postmortem urine samples.
 Conclusions: The present method is a rapid, simple, easy and sensitive procedure and can be used in clinical and forensic toxicology laboratories as routine method for qualitative and quantitative analysis of methadone.

Analytical Approaches for the Determination of Buprenorphine, Methadone and Their Metabolites in Biological Matrices

“…This rapid and automatable method is a potential tool for routine quantification of BUP and its metabolites. Nevertheless, the most commonly employed sample pretreatment for the monitoring of BUP, MTD and their metabolites in biological matrices are liquid-liquid extraction (LLE) [18][19][20][21][22][23]26,40,47,49,50,[52][53][54]56,60,61,63,65,68,69,71,74,76,77,80,[88][89][90][91][92] and solid-phase extraction (SPE) [7,24,28,38,41,[43][44][45][46]48,55,68,72,73,75,[93][94][95]. The major benefits of LLE are its simplicity a...…”

“…Table 1 summarizes the details based on the use of LC techniques utilized for BUP and MTD measurement. LC can be coupled with ultraviolet (UV) [40][41][42][43]54], photodiode array detector (PAD) [40], fluorescence (FL) and electrochemical (EC) [29,38] MS detection [7,13,15,18,[23][24][25][26][27][28]49,50,52,56,[60][61][62]64,65,[68][69][70][71][72][73]88]. Reversed-phase columns (C 18 or C 8 columns) with spherical sorbent particles are popular for the determination of BUP, MTD and their metabolites.…”