Artifacts in the determination of intravenous anesthetics by gas chromatography-mass spectrometry: Tramadol, the correlation between the structures of metabolites and impurity substances

GC–MS quantification of ketamine, norketamine, and dehydronorketamine in urine specimens and comparative study using ELISA as the preliminary test methodology

“…Since 1970s, several analytical methods for the determination of K and its metabolites in human urine, plasma, and hair have been developed. These methods were based on gas chromatography with flame-ionization detector (GC-FID) [6], nitrogen-phosphorus detector (GC-NPD) [7], and high-performance liquid chromatography (HPLC) [8]. More specific methods using mass spectrometer as the detector, i.e.…”

“…More specific methods using mass spectrometer as the detector, i.e. gas chromatography-mass spectrometry (GC-MS) [6,7,[9][10][11][12][13][14][15][16][17][18] and liquid chromatography-mass spectrometry (LC-MS) methods [18,19], have been reported. More recently, highly specific approaches based on liquid chromatography-tandem mass spectrometry (LC-MS-MS) [20] and headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS) [21] have also been advocated as effective "screening" methods.…”

Quantitative detection of ketamine, norketamine, and dehydronorketamine in urine using chemical derivatization followed by gas chromatography–mass spectrometry

“…Analysis of KT and/or its demethylated metabolites has been accomplished by high-performance liquid chromatography [8][9][10][11][12] and liquid chromatography-mass spectrometry methods [13]. The analytes were also detected by gas chromatography with flame ionization detection [14,15], nitrogen phosphate detection [16], electron-capture detection [5], or by mass spectrometry detection with derivatization [6] or without derivatization [17][18][19][20][21][22]. Most of the above methods involved liquid-liquid extraction (LLE) or solid-phase extraction (SPE) for sample preparation; a method combining solid-phase microextraction and GC-MS has been reported, too [23].…”

Membrane Sensors for the Selective Determination of Thiopental

“…These data compared favorably with the results obtained with the spectrophotometric method. 11 With the proposed potentiometric method, the accuracy of the results (recoveries 99.7 -100%) is much better than those obtained by gas chromatography (recoveries 81 -104%), 17 HPLC (recoveries 88.6 -94%) [5][6][7][8] and spectrophotometry (recoveries 98.7 -101.1%). 11 These characteristics suggest an interest of direct potentiometry with the proposed sensors for routine pharmaceutical work.…”

“…5,8 Recent HPLC assays, even after overcoming most of these problems, are not completely reliable, and do not have the short process-time required in most of the above-mentioned indications. 9,10 A few other methods are available for determining thiopental, including spectrophotometric, [11][12][13] fluorometric, 14 stripping voltammetry, 15 coulometric, 16 gas chromatography (GC) 17 and high-performance capillary electrophoresis. 18 The potentiometric procedure has not been reported concerning the determination of thiopental.…”