GC–MS

The chemical analysis of organic compounds in environmental samples is often targeted on predetermined analytes. A major shortcoming of this approach is that it invariably excludes a vast number of compounds of unknown relevance. Nontargeted chemical fingerprinting analysis addresses this problem by including all compounds that generate a relevant signal from a specific analytical platform and so more information about the samples can be obtained. A DHS−TD−GC−MS method for the fingerprinting analysis of mobile VOCs in soil is described and tested in this article. The analysis parameters, sorbent tube, purge volume, trapping temperature, drying of sorbent tube, and oven temperature were optimized through qualitative and semiquantitative analysis. The DHS−TD–GC−MS fingerprints of soil samples from three sites with spruce, oak, or beech were investigated by pixel-based analysis, a nontargeted data analysis method.

The Column spoke to Ricardo Lopez from the University of Zaragoza, in Spain, about his work characterizing the composition of the vapours from wine during consumption using an automated gas chromatography–mass spectrometry (GC–MS) technique.

This study describes the analysis of fragranced washing detergent and washing powder using probe-based headspace and immersive sorptive extraction, in conjunction with analysis by thermal desorption–gas chromatography–mass spectrometry (TD–GC–MS). As well as discussing the differences between the two samples, the analyte ranges covered by headspace and immersive sampling are compared.

The chemical messages that animals use to communicate can trigger a range of responses in members of the same species. The Column spoke to Jorge Saiz from the Centre of Metabolomics and Bioanalysis (CEMBIO) at the University San Pablo CEU, Spain, about his research into the chemical secretions of lizards and the role of gas chromatography–tandem mass spectrometry (GC–MS/MS) in his work.

These five tips could improve your for gas chromatography methods.

The antimicrobial triclosan is present in myriad personal care products, many of which are disposed of down household drains and travel to wastewater treatment plants. This article describes a simple and rapid method for the preparation and extraction of triclosan and methyl triclosan from the complex matrix of biosolids and paper mulch samples followed by analysis using GC–MS/MS.

In this study, an empirical assessment of summation integration (using the lowest baseline point in user-defined tR windows) was conducted involving 490 low-pressure GC–MS/MS analyses of 70 pesticides in 10 common fruits and vegetables over the course of 10 days.

With a simple liquid extraction approach and a short, 13-min GC method, dried blood spots can be analyzed effectively and rapidly. This method demonstrates that dried blood spot cards are an effective technique for toxicological studies.

We present an empirical assessment of summation integration involving 490 low-pressure GC–MS/MS analyses of 70 pesticides in 10 common fruits and vegetables over the course of 10 days.

As the legalization of medicinal cannabis continues to sweep across the United States, an urgent need has developed for fast, accurate and efficient analytical testing. In addition to testing for contaminants and potency, there is also interest in the determination of terpene identity and concentration levels present in different strains of cannabis. Terpenes have been shown to have therapeutic uses for treatment of different medical conditions ranging from cancer and inflammation, to anxiety and sleeplessness. It is believed that the combination of terpenes and cannabinoids in cannabis produce a synergistic effect with regards to medical benefits. The traditional testing method for terpenes in plant materials involves a solvent-based extraction followed by GC analysis. In this work, headspace solid phase microextraction (HS-SPME) was used to identify and quantify terpene content in cannabis. The HS-SPME method provided several advantages over solvent extraction in that it provided a cleaner analysis, free of interferences from co-extracted matrix, and was non-destructive to the sample. A cannabis sample of unknown origin was first analyzed qualitatively by HS-SPME and GC-MS. Spectral library matching and retention indices were used to identify 42 different terpenes. Quantitative analysis was then performed for several selected terpenes using spiked samples. Method accuracy was >90%, with reproducibility of

In this study, a simple method was used for extraction and concentration of trace organic compounds in water, followed by injection using a coiled wire filament and GC–MS analysis. Common semivolatile organic compound contaminants at low parts-per-billion levels were detected in less than 10 min.

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.