Hollow‐fiber liquid‐phase microextraction and gas chromatography‐mass spectrometry of barbiturates in whole blood samples

Abstract

Here, we present a method for measuring barbiturates (butalbital, secobarbital, pentobarbital, and phenobarbital) in whole blood samples. To accomplish these measurements, analytes were extracted by means of hollow-fiber liquid-phase microextraction in the three-phase mode. Hollow-fiber pores were filled with decanol, and a solution of sodium hydroxide (pH 13) was introduced into the lumen of the fiber (acceptor phase). The fiber was submersed in the acidified blood sample, and the system was subjected to an ultrasonic bath. After a 5 min extraction, the acceptor phase was withdrawn from the fiber and dried under a nitrogen stream. The residue was reconstituted with ethyl acetate and trimethylanilinium hydroxide. An aliquot of 1.0 μL of this solution was injected into the gas chromatograph/mass spectrometer, with the derivatization reaction occurring in the hot injector port (flash methylation). The method proved to be simple and rapid, and only a small amount of organic solvent (decanol) was needed for extraction. The detection limit was 0.5 μg/mL for all the analyzed barbiturates. The calibration curves were linear over the specified range (1.0 to 10.0 μg/mL). This method was successfully applied to postmortem samples (heart blood and femoral blood) collected from three deceased persons previously exposed to barbiturates.

Ultrasound and surfactant‐assisted dispersive liquid–liquid microextraction prior to poly(ethylene oxide)‐mediated stacking in CE for highly sensitive determination of barbiturates in human fluids

“…The proposed method exhibited an excellent response within a linear range of 1−100 nM for the accurate quantification of pentobarbital, secobarbital, amobarbital, butalbital, and phenobarbital and high reproducibility for the separation of the drug mixture. Notably, the LODs (S/N = 3) of pentobarbital, secobarbital, amobarbital, butalbital, and phenobarbital achieved by the proposed system were lower than those reported using other methods (Table 2) [5, 32–35]. USA‐DLLME demonstrated excellent sample clean‐up capability and simplicity of operation.…”

Detection of Flunitrazepam in Biological Fluids and Beverages:A Review

“…Based on the previous exploration of the critical role of FLU extraction methods on their assay results, [42][43][44][45] several reports have focused on the optimization of extraction methods. In response to the apparent limitations of conventional analytical methods for FLU and its metabolites, Nguyen and colleagues optimized and improved the conventional SPE-GC-MS method for the detection of FLU and its metabolites in urine.…”

Determination of Barbiturates in Biological Specimens by Flat Membrane-Based Liquid-Phase Microextraction and Liquid Chromatography-Mass Spectrometry

“…In recent decades, the analysis of barbiturates has attracted extensive attention worldwide, and several methods such as ultraviolet–visible spectroscopy (UV-Vis) [8], capillary electrophoresis (CE) [9,10,11,12], liquid chromatography (LC) [13,14], liquid chromatography–mass spectrometry (LC-MS) [15], and gas chromatography–mass spectrometry (GC-MS) [16,17,18,19,20] have been reported for the determination of barbiturates in biological specimens. Traditional technologies such as UV-Vis spectroscopy is still widely used in forensic science for its convenience but it lacks specificity and sensitivity.…”

“…On the other hand, LPME, which is considered as a “green” extraction technique, has attracted widespread attention for its good purification capability, economical efficiency, and easy operation [18,28,29,30,31,34]. Until now, LPME has already been applied in the purification and enrichment steps in different biological samples [8,16,18,23,34]. For example, Zarei et al adopted a dispersive liquid–liquid microextraction (DLLME) technique combined with spectrophotometric analysis for the determination of trace amounts of barbituric acid in human serum [8].…”

“…For example, Zarei et al adopted a dispersive liquid–liquid microextraction (DLLME) technique combined with spectrophotometric analysis for the determination of trace amounts of barbituric acid in human serum [8]. Hollow fiber–liquid phase microextraction (HF-LPME) was also developed to isolate barbiturates in hair [18], blood [16], and liver samples [35], and coupled with GC-MS, satisfactory results can be reached.…”