We describe a quantitative screen for hypnotic-sedative drugs in which we use capillary gas chromatography with a nitrogen-phosphorus detector (GC/NPD) as the primary method and capillary gas chromatography-mass spectrometry (GC-MS) for confirmation. GC retention times of the acid-extracted underivatized drugs were stable (CVs less than 1%), and the detector response varied linearly over a 20-f...

We examined the decomposition behavior of 1-acyl-substituted derivatives d-lysergic acid diethylamide (LSD), such as 1-cyclopropanecarbonyl LSD (1cP-LSD), 1-acetyl (ALD-52), and 1-propionyl (1P-LSD) through gas chromatography/mass spectrometry (GC/MS). It was reported previously that in methanol, 1cP-LSD completely decomposed into during GC/MS. found remained undecomposed GC/MS, extent varied b...

Smoking marijuana during pregnancy can cause health problems in the neonate. The detection of exposure can guide treatment to meet the short- and long-term medical and social needs. Umbilical cord tissue was analyzed for 11-nor-delta-9-carboxy-tetrahydrocannabinol (THC-COOH) by gas chromatography-mass spectrometry (GC-MS), and compared with ultra-sensitive enzyme-linked immunosorbent assay (ELI...

The present review represents a concise and complete survey of the literature covering 2004-2009, concerning the mass spectrometric techniques involved in the structural investigation of renal calculi. After a short presentation of the fundamental mass spectrometric techniques (MALDI-TOF, QTOF, MS-MS) as well as hyphenated methods (GC-MS, LC-MS, CE-MS), an extensive study of the urinary proteom...

For more than a decade, we have developed stable isotope dilution mass spectrometry methods to quantify key intermediates in cholesterol and bile acid biosynthesis, mevalonate and oxysterols, respectively. The methods are more sensitive and reproducible than conventional radioisotope (RI), gas-chromatography (GC) or high-performance liquid chromatography (HPLC) methods, so that they are applica...

To investigate the utility of comprehensive GC×GC gas chromatography metabolomics in finding varietal markers among volatile compounds non-aromatic red wines, representative samples two most important Croatian monovarietal Plavac mali and Teran, were subjected to analysis by both conventional chromatography–mass spectrometry (GC-MS) two-dimensional with time-of-flight mass (GC×GC-TOF-MS) after ...

Materials and methods To analyze the catalytic activity of PHGDH on possible alternative substrates, we conducted in vitro biochemical assays on recombinant human PHGDH. The reaction rate in the reductive direction with various substrates was monitored based on NADH consumption, measured by absorbance at 340 nm. The identity and chirality of products were analyzed by liquid chromatography-mass ...

Comprehensive Gas Chromatography-Time-of-Flight Mass Spectrometry (GC×GC-TOFMS) methodology has been refined for the analysis of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in samples with different matrices. This is specifically for application in developing countries where access to gas chromatography-high resolution mass spectrometry (GC-HRMS) and high...

A method for the determination of 42 hazard residues required by 'Japan Positive List System' in bottled water was described. Hazard compounds in bottled water were extracted with a solid phase extraction step using C18 disks. Determination was carried out by gas chromatography/mass spectrometry (GC/MS) and liquid chromatography-tandem mass spectrometry (LC/MS/MS). The disk extraction has high ...