GC–MS

Improve results by optimizing the injection, column, and detection.

This study describes the recovery of compounds above the boiling point of naphthalene achieved by optimizing the thermal desorption chemistry for the determination of volatile organic compounds ranging from C3 to C26 in soil gas samples using Method TO-17. Figures of merit such as breakthrough, precision, linearity, and detection capability are presented, in addition to an evaluation of its real-world capability at sites with moderate diesel and semivolatile polynuclear aromatic hydrocarbon (up to pyrene) contamination, in the presence of high humidity. This research has provided a means to determine a more representative composition of soil gas.

A gas chromatography–time-of-flight mass spectrometry method was developed to screen for and quantify regulated allergens in approximately 5 min. This method used a short and narrow chromatographic column along with mathematical deconvolution of the TOF-MS data to separate the target allergens from each other in the standards and from matrix interference in samples.

This study demonstrates that GC–TOF-MS can be a useful approach to generate comprehensive fragrance profiles of essential oils. Peak deconvolution enables discrimination between closely eluted compounds, and soft electron ionization, assisted by comparison of ion ratios, makes it possible to discriminate between isomeric monoterpenes with very similar mass spectra at conventional 70-eV ionization energies.

A look at the use of field-portable GC–MS with solid-phase microextraction, purge-and-trap, thermal desorption, and heated headspace sampling techniques to provide a fast response for in-field analysis of SVOCs in a wide variety of environmental-type samples including potable waters, tea, plants, and road gravel.

The development of various analytical MS methods to investigate the chemical composition of liquids used in electronic cigarettes and characterize their quality is presented in this study.

This study describes the need to recover compounds above the boiling point of naphthalene by optimizing the thermal desorption chemistry for the determination of VOCs from C3 to C26 in soil gas samples using Method TO-17. Figures of merit, such as breakthrough, precision, linearity and detection capability will be presented, in addition to evaluating its real-world capability at sites with moderate diesel and semi-volatile polynuclear aromatic hydrocarbon (up to pyrene) contamination, in the presence of high humidity.

Enhanced chromatographic resolution (GC×GC), increased resolving power with high-resolution TOF-MS, and software designed to leverage these attributes are combined to provide data that are easy to process and interpret.

A method based on thermal desorption with gas chromatography–time-of-flight mass spectrometry (GC–TOF-MS) can elucidate how key volatiles vary with the size of the melon pieces. Such analytical information is of value in efforts to improve the quality and safety of ready-to-eat foods.

This study focuses on United States Environmental Protection Agency (US EPA) Method 524.3 for volatile organic compounds (VOCs) in water using gas chromatography–mass spectrometry (GC–MS).

This method allows for quick sample preparation of fish samples for the fast analysis of almost 200 targeted contaminants, including PAHs, PCBs, PBDEs, and flame retardants.

Many "minor" variables in GC–MS analysis can be optimized to improve selectivity or sensitivity.

A new procedure is proposed that provides identity parameters for headspace-applicable residual solvent Class 1 and Class 2 compounds addressed in the current US Pharmacopeia <467> method.

This article demonstrates the superiority of the GC-MS approach over spectrophotometry.

A selective and highly sensitive capillary gas chromatographic-mass spectromic approach has been developed for the detection of PBDEs and PBBs that utilizes dissociative resonance electron capture and selected ion monitoring.

A novel method that significantly improves the accuracy and reliability of "unknown" compound identification for volatile organic compounds by GC-MS is described.

A GC-MS procedure has been developed, optimized, and applied to characterization of oil binders in paintings.

Researchers at the Universit? di Camerino in Camerino, Italy have developed a new GC-MS and LC-MS technique for the determination of five ink photoinitiator residues: 2-isopropylthioxanthone (ITX), benzophenone, 2-ethylhexyl-4-dimethylaminobenzoate (EHDAB), 1-hydroxycyclohexyl-1-phenyl ketone (IRGACURE 184) and ethyl-4-dimethylaminobenzoate (EDAB) in packaged beverages.

This month, Chromatography Online's Technology Forum focuses on the topic of Gas Chromatography (GC). Joining us for this discussion is Sky Countryman, GC Product Manager at Phenomenex; Gary Harland, Tandem Quadrupole MS Product Manager at Waters; a Team of Experts from Thermo Fisher Scientific; and Tom Gluodenis and Terry L. Sheehan from Agilent Technologies Life Sciences & Chemical Analysis Group.

This article presents modified GC-MS method for the analysis of volatile organic compounds by method 8260; this method will dramatically increase instrumental throughput.

The volatile extraction market consists of three techniques: purge and trap, headspace, and thermal desorption equipment. These systems are often employed as a sampling method for gas chromatography (GC) instrumentation but are also used with IR detectors, electrochemical sensors of electronic noses, and mass spectrometers.

Negative chemical ionization GC-MS, used in conjunction with automated cold-on-column injection, provides efficient and sensitive quantification of explosive residues for environmental and forensic applications.

Gas chromatography (GC) coupled to time-of-flight mass spectrometry (TOF-MS) offers unique solutions for various analytical applications including the analysis of food quality, authenticity and safety markers. This article provides a general overview of TOF-MS basic features, highlighting its advantages and limitations compared with GC conventional mass analyzers. Examples of recent results obtained selected food contaminants and flavor components are described illustrate the potential of this recently introduced technique.

Ultrahigh performance liquid chromatography (LC)–time-of-flight mass spectrometry –(TOF-MS) and gas chromatography (GC)–TOF-MS are powerful approaches for screening target compounds and identifying or characterizing nontarget compounds in complex mixtures. The combination of accurate mass data and newly developed software enables truly generic screening methods with TOF-MS, and the confident detection, identification, and confirmation of small molecules in a range of application areas.

Doping testing is now an accepted fact of sporting life - whether in major international competitions, such as the Olympics, or in regular events at the national level. Athletes who cheat by taking banned substances risk harming their careers and their health. They also bring their country and their sport into disrepute. A reliable and reproducible scientific system for doping testing, backed up by sanctions, helps fight the culture of drugs in sport so that athletes can participate on a level playing field.

Analytical technologies have been applied to many problems of the modern world, though usually in the domain of the laboratory or to regulate production on the factory floor. However, modern instrumentation can provide valuable information in many other settings as well. Security applications demand sensitive information, accurate information and fast information. These are precisely the kinds of problems that instrumentation has been solving in the research setting for decades. The application of analytical technology to the security of nations, facilities, and people has become an important segment of the industry.

Gas chromatography-mass spectrometry using a single-quadrupole instrument is the workhorse technique of the environmental lab. It normally falls short for applications that require high mass accuracy. It is shown here that with proper calibration techniques, this technique can indeed readily obtain high mass accuracies to within a few millidaltons and become a powerful tool for unknown compound identification.

A method for the identification of key volatile organic compound (VOC) markers associated with infection by Neisseria meningitidis bacteria by gas chromatography–mass spectrometry (GC–MS) was developed. Headspace samples of bacterial VOCs were trapped on triple-sorbent bed tubes and then thermally desorbed into a laboratory GC–MS system for separation. Identification was carried out by comparison of GC retention time and electron ionization mass spectra to the National Institute of Standards and Technology (NIST) database. Further confirmation was obtained by GC–MS of known standard chemicals. A total of 75 VOCs were detected, five of which can be considered key VOC markers for Neisseria meningitidis. These peaks were identified as 1,2-dimethylcyclopropane, 2-methylpropanal, methacrolein, N-2-dimethyl-1-propanamine, and 3-methylbutanal by the NIST database.

The author configured a purge-and-trap GC-MS system that simultaneously improved chromatographic resolution and reduced analysis time.