Mass spectrometry has long been used in clinical laboratories. The first important applications were the use of gas chromatography–mass spectrometry (GC-MS) for drug screening and the diagnosis of organic acid metabolic disorders. More recently liquid chromatography–mass spectrometry [LC-MS; liquid chromatography–tandem mass spectrometry (LC-MS/MS)] has been introduced successfully into clinica...

Different solvent extracts of a red algae, Hypnea flagelliformis,and two brown algae, Cystoseira myrica and Sargassum boveanum, collected from the Persian Gulf coast were subjected to different bioassays including: 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay, antibacterial and antifungal activity by thin layer chromatography (TLC)-bioautography, agar disc diffusion (ADD) ...

Acetylation with acetic anhydride, under both aqueous and anhydrous conditions, has been utilized to derivatize various biogenic amines and psychotropic drugs for subsequent analysis by gas chromatography (GC) or gas chromatography-mass spectrometry (GC-MS). Under basic aqueous conditions, acetic anhydride derivatizes phenols and amines but not alcohols; under anhydrous conditions, all three fu...

Volatile compounds emanated from human skin were studied by gas chromatography/mass spectrometry (GC/MS). The purpose of this study was to identify compounds that may be human-produced kairomones which are used for host location by the mosquito, Aedes aegypti (L.). The procedure used to collect volatiles was chosen because of prior knowledge that attractive substances can be transferred from sk...

Gas chromatography-mass spectrometry (GC-MS) was used to detect 2-docosanol, a secondary alcohol characteristic of Mycobacterium xenopi, in 7 of 10 analyzed drinking water samples culture positive for that species. GC-MS was also used to detect tuberculostearic acid. Both of these chemical markers were analyzed as halogenated derivatives in the negative-ion-chemical-ionization mode. The numbers...

An overview is presented of gas chromatography/mass spectrometry (GC/MS) and liquid chromatography/mass spectrometry (LC/MS), the two major hyphenated techniques employed in metabolic profiling that complement direct 'fingerprinting' methods such as atmospheric pressure ionization (API) quadrupole time-of-flight MS, API Fourier transform MS, and NMR. In GC/MS, the analytes are normally derivati...

Direct gas chromatographic (GC) analysis of thermally labile N-carbamates is studied by using fast GC with cold on-column injection. With the greatly reduced injection temperature, short column lengths, high flow rate, and fast temperature-programming rate, the exposure of carbamates to high temperature is reduced and degradation can be avoided. Nine N-carbamates in EPA Method 531 are eluted wi...

abstract: a combined gas chromatography-mass spectrometry (gc-ms) with headspace solid-phase micro extraction (spme) method has been employed for the analysis of the flavor volatiles of three different rice cultivar, including two modified iranian rice cultivars and hashemi rice cultivar during gelatinization. the proposed combination provided a powerful system for easy and rapid screening of a...