Development of a Gas Chromatographic--Mass Spectrometric Drug Screening Method for the N-Dealkylated Metabolites of Fentanyl, Sufentanil, and Alfentanil

Abstract

A sensitive, specific urinary assay for fentanyl, sufentanil, and alfentanil based on their N-dealkylated metabolites is described. Norfentanyl, norsufentanil-noralfentanil, and 2H5-norfentanyl are synthesized and characterized by standard analytical techniques. Derivatization of these secondary amines to yield the pentafluorobenzamides produces stable products with good gas chromatographic properties and unique, high-mass fragments in their mass spectra. These properties are utilized to develop a drug screening procedure based on gas chromatography-mass spectrometry to detect these major metabolites in human urine. The metabolites are isolated from urine samples by a liquid-liquid extraction procedure. The method allows for detection of metabolite concentrations as low as 0.3 ng/mL.

Determination of fentanyl in human plasma and fentanyl and norfentanyl in human urine using LC–MS/MS

“…Fentanyl and/or its main metabolite, norfentanyl ( Fig. 1) have been determined using GC [1], HPLC/UV [2][3][4][5], GC/MS [6][7][8], LC-MS/MS [9][10][11][12] and immunoassays [13,14]. HPLC and immunoassays did not offer the high sensitivity required for low dose studies of fentanyl, GC/MS give good sensitivity but requires long run times.…”

Highly sensitive gas chromatographic—mass spectrometric screening method for the determination of picogram levels of fentanyl, sufentanil and alfentanil and their major metabolites in urine of opioid exposed workers

“…During the last decade, instrumental analyses, including both liquid and gas chromatographic separations with diverse detection systems, have been developed and validated, focussing on the identification and quantification of the fentanyl-like compounds and their metabolites, mainly in human plasma. Chromatographic assays using mass-selective detection procedures are highly specific and accordingly sensitive but in general limits of quantification of 20-300 pg/ml are reported, [21][22][23]28,[33][34][35] which were suspected to be still unsatisfactory for the present study purpose. In our newly developed analytical procedures, only 1 ml of urine was required to achieve limits of detection (LODs) of 2.5 pg fentanyl/ml, 2.5 pg sufentanil/ml and 7.5 pg alfentanil/ml.…”

“…Derivatization of the secondary amine functionalities of the nor-metabolites norfentanyl and norsu(al)fentanil and the internal standard d 5 -norfentanyl was carried out following the procedure of Valaer et al [21] with some modifications. Briefly, 100 l of a 0.1 M pentafluorobenzoyl chloride solution in chloroform was added to the residues but no heating was applied.…”

Analysis of anaesthetics and analgesics in human urine by headspace SPME and GC

“…In addition, fentanyl is progressively more often used as an alternative drug of abuse from opiate users. Especially due to the increasing availability of the fentanyl transdermal patches, the cases of fentanyl misuse and abuse are rapidly increasing [2,12,36,37]. As a result the determination of the levels of these drugs in urine is of both clinical and toxicological interest including the examination of post mortem cases and the forensic control of human and animals (e.g.…”