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...

background: the present study was the first attempt for determination and measurement of pesticide residues in tomatoes used in salad production plants in isfahan, central iran. methods: a multiresidue method based on modified quechers (quick, easy, cheap, effective, rugged and safe) sample preparation, followed by gas chromatography mass spectrometry (gc–ms) was developed and validated for the...

background and objectives: in the production process of foods rich in carbohydrates and some other foods containing precursors of acrylamide formation, there is the possibility of acrylamide creation, which is a mutagen and carcinogen material. this study aims to introduce and optimize a new method for determining acrylamide in potato chips using xanthydrol as a derivative representative with g...

the aim of this study was to investigate the removal of toluene from air through nano-graphene modified by ionic liquid (ng-il). the batch adsorption experiments in glass bottle of gas chromatography equipped with flame ionization detector (gc-fid) were used. graphene ultrahigh-quality synthesized by substrate-free gas-phase method in a single step and graphene sheets were deposited with ionic-...

Gas chromatography (GC) is a widely applied technique in many branches of science and technology. For over half a century, GC has played a fundamental role in determining how many components and in what proportion they exist in a mixture. However, the ability to establish the nature and chemical structure of these separated and quantified compounds is ambiguous and reduced, and requires a spect...

We describe a new method for visualization of gas flows based on infrared absorption and gas-correlation techniques. This result is a gray-scale or false color-coded image showing the distribution of a specific gas in the area studied. A sequence of images showing the workplace test setup with a turbulent flowing gas is presented.

From a traditional perspective, mass spectrometry and polymer analysis appear to be incompatible. Mass spectrometry requires gas-phase ions for a successful analysis and polymers are composed of large, often entangled macromolecules that are not readily converted to gas-phase species. Despite these natural difficulties, mass spectrometry techniques have been developed to characterize the chemic...