in this study, a simple and reliable method by gas chromatograph–mass spectrometry (gc–ms) was developed for the fast and regular identification of 3, 4-mdma impurities in ecstasy tablets. in so doing, 8 samples of impurities were extracted by diethyl ether under alkaline condition and then analyzed by gc–ms. the results revealed high mdma levels ranging from 37.6% to 57.7%. the gc-ms method sh...

The term ‘dimension’ in the above titles refers to the use of a ‘dimension of chromatography’ – or put more simply, a column – or for multidimension – two or more columns. In the broad sense, a ‘dimension of analysis’ is any technique that provides independent analysis capability. So FTIR, MS, and GC are discrete dimensions; they can be operated independently to provide some measure of analysis...

Gas Chromatography (GC) is a mature analytical technology used predominately for separating and quantifying the components of complex organic chemical mixtures. The addition of mass selective detectors has extended the use of GC to include compound identification. A wide range of columns and sample introduction techniques allow GC to solve most analytical problems for volatile and semi-volatile...

Comprehensive two-dimensional gas chromatography (GC × GC) is one of the most powerful analytical tools for the analysis of organic compounds in complex matrices. The technique is based on continuous collection of the effluent from a GC column and periodic reinjection of small portions of the effluent to a second column of different properties. The process is repeated at a rate fast enough that...

The biggest limitation to conventional gas chromatography (GC) is limited peak capacity, making the analysis of complex mixtures a difficult or even impossible task. Comprehensive two-dimensional gas chromatography (GC×GC) significantly increases peak capacity and resolution, improves sensitivity and generates structured 3D chromatograms. This is achieved by connecting two columns coated with d...

The detailed characterisation of middle distillates is essential for a better understanding of reactions involved in refining process. Owing to higher resolution power and enhanced sensitivity, comprehensive two-dimensional gas chromatography (GC x GC) is a powerful tool for improving characterisation of petroleum samples. The aim of this paper is to compare GC x GC and various ASTM methods -- ...

tional scanning of large genes by extensive PCR multiplexing and two-dimensional electrophoresis: application to the RB1 gene. Human Molecular Genetics 5: 755}761. van OrsouwNJ, Dhanda RK, Rines DR et al. (1998) Rapid design of denaturing gradient-based two-dimensional electrophoretic gene mutational scanning tests. Nucleic Acids Research 10: 2398}2406. Vijg J and van Orsouw NJ (1999) Two-dimen...

Sample Types LC/MS systems facilitate the analysis of samples that traditionally have been difficult to analyze. Despite the power and usefulness of gas chromatography/mass spectrometry (GC/MS), many compounds are impossible to analyze with GC/MS. LC/MS significantly expands the effective analytical use of mass spectrometry to a much larger number of organic compounds. Gas chromatography and GC...