Analysis of Fentanyl in Urine by DLLME–GC-MS

Abstract

Fentanyl is a synthetic narcotic anesthetic ∼80-100 times more potent than morphine. Owing to the potential for its abuse, the drug may be included in a forensic toxicology work-up, which requires fast, precise and accurate measurements. Here, the stability of fentanyl was assessed when stored at three different temperatures (-20, 4 and 25°C) in synthetic urine. Stability at those three temperatures was demonstrated over 12 weeks upon analysis by gas chromatography-mass spectrometry with a deuterated internal standard (fentanyl-D5) utilizing three different extraction techniques: liquid-liquid extraction (LLE), solid-phase extraction and dispersed liquid-liquid microextraction (DLLME). The DLLME method was then optimized before use in the analysis of fentanyl in urine samples obtained from autopsy cases at the El Paso County Coroner's Office. Accuracy of the DLLME method was assessed by completing spike and recovery studies at three different fortification levels (10, 100 and 250 ng/mL) with excellent recovery (89.9-102.6%). The excellent comparability between DLLME and LLE is demonstrated (Bland-Altman difference plot with a mean difference of 4.9 ng/mL) and the use of this methodology in the analysis of forensically relevant samples is discussed.

Gas Chromatography-Mass Spectrometry Analysis of Synthetic Opioids Belonging to the Fentanyl Class: A Review

“…In 2015, an effort involving several laboratories that included the University of Colorado, Colorado Springs, the Beth-El College in Colorado Springs and the El Paso County Coroner's Office in Colorado Springs published their study on the stability of fentanyl in synthetic urine making use of a dispersed liquid-liquid microextraction (DLLM) approach. [94] In their work the authors compare the extraction efficiencies of DLLM to be comparable to those obtained when using traditional liquid-liquid (LLE) and SPE extraction protocols. Their stability studies on fentanyl involved a 12-week period of assessment, and the results show the high efficiency of the approach with recovery values for an initial fentanyl concentration of 1000 ng .…”

Ten Years of Fentanyl-like Drugs: a Technical-analytical Review

“…Rarely, other microextraction procedures were employed, such as hollow fiber-assisted liquid-phase micro extraction 44,45 (HF-LPME), surfactant-assisted pulsed two-phase electro membrane extraction 46 (SA-PEME), dispersive liquid-liquid microextraction 45,47 (dLLME) and microextraction in a packed syringe 48 (MEPS). MEPS 48 employed a low volume of samples, reaching low limits of quantification.…”

“…MEPS 48 employed a low volume of samples, reaching low limits of quantification. dLLME 45,47 is a straightforward and low-cost technique.…”

Direct Coupling of Bio-SPME to Liquid Electron Ionization-MS/MS via a Modified Microfluidic Open Interface

“…Fentanyl and its derivatives have been quantified in biological fluids with GC-MS or LC-MS. − In LC-MS/MS, internal standards are used to assess matrix effects (ME) coming from the ionization step. The chromatographic column provides the required resolution and sensitivity for analyte separation, with limits of detection below 1 ng·mL –1 .…”