Quasi-Simultaneous and Automated Measurement of Primary Amines and Short-Chain Aldehydes Emission by Dynamic SPME On-Fiber Derivatization Coupled With a Flow-Cell.

An automated method was developed to simultaneously measure primary amines and short-chain aldehydes emission from foam and rubber samples in one experiment. The technique involved dynamic solid-phase microextraction (SPME) on-fiber derivatization coupled with a flow-cell unit. The parameters of the dynamic SPME on-fiber derivatization method were optimized, including SPME coating, derivatization agents loading temperature, loading time, and dynamic SPME extraction time.

Automated method for short-chain aldehydes emission measurement by dynamic solid-phase microextraction on-fiber derivatization GC-MSD coupled with a flow-cell.

A novel automated method was developed to test short-chain aldehyde emissions using a chamber and a flow-cell coupled with a dynamic solid-phase microextraction (SPME) on-fiber derivatization technique. Calibration curves of short-chain aldehydes were developed for quantitation of target analytes, including formaldehyde, acetaldehyde, propionaldehyde, and acrolein emitted from the chamber outlet. The linearity range for the aldehydes was 0.

Quantification of the composition of liquid hydrocarbon streams: Comparing the GC-VUV to DHA and GCxGC.

Hydrocarbons analysis is important in the oil and gas industry, as stream composition has a strong impact on plant operations. The composition of hydrocarbon streams vary across a plant, which makes the selection of analytical methods challenging. Traditional methods for the evaluation of liquid hydrocarbon streams include the Detailed Hydrocarbon Analysis (DHA); however, non-traditional methods, such as comprehensive gas chromatography (GCxGC), are also utilized in the chemical industry, including Dow.

Comprehensive two dimensional gas chromatography review.

Advances, developments and applications in 2-D comprehensive GC (GC x GC) from 2007 through October 2008 are reviewed, with emphasis on modulation, and data handling, and applications of current relevance. Industrial perspectives as well as suggestions where further developments would be beneficial are summarized in the concluding remarks.

Dual-purpose gas chromatographic injection device for pressurized liquid and gas injection.

A dual-purpose gas chromatographic injection device, capable of injecting pressurized liquid sample of up to 5000 psig and gas sample with a volume as high as 5000 microL, has been successfully developed and implemented. The injection device is synergized by the effectiveness of a classical flash vaporization of a syringe injection and the reliability of a proven rotary valve. Depending on the matrix involved, this injection device employs either a commercially available four-port internal valve for liquid sampling or a six-port external valve for gas sampling, a modified removable needle used in standard liquid syringe, and an auxiliary flow stream that can be either mechanical or electronic flow controlled for solute transfer.

Determination of short-chain branching content in polyethylene by pyrolysis comprehensive multidimensional gas chromatography using low thermal mass column technology.

A research effort was undertaken to utilize the pyrolysis process to create fragments of polyethylene that could be indicative of branching, and allow quantitiation of said short-chain branches by pyrolysis comprehensive 2-D GC (Py-GC x GC). Several strategies for sample introduction and pyrolysis such as the in-column pyrolysis device and the programmed temperature vaporizer (PTV) were studied. The chromatographic separations were executed using low-thermal mass (LTM) comprehensive 2-D GC (GC x GC).

A new decoupling method for accurate quantification of polyethylene copolymer composition and triad sequence distribution with 13C NMR.

(13)C NMR is a powerful analytical tool for characterizing polyethylene copolymer composition and sequence distribution. Accurate characterization of the composition and sequence distribution is critical for researchers in industry and academia. Some common composite pulse decoupling (CPD) sequences used in polyethylene copolymer (13)C NMR can lead to artifacts such as modulations of the decoupled (13)C NMR signals (decoupling sidebands) resulting in systematic errors in quantitative analysis.

Universal and discriminative detection using a miniaturized pulsed discharge detector in comprehensive two-dimensional GC.

A miniaturized pulsed discharge detector (Mini-PDD) has been successfully demonstrated for comprehensive 2-D GC (GC x GC) analysis of pyrolysis gasoline and the pyrolysis GC x GC analysis of a polyethylene copolymer. The detector cell volume of the Mini-PDD is reduced to 25% of the Valco plug-in PDD D-3. An n-C11 peak width at base is 96 ms for the Mini-PDD, about 23% larger than a peak width of 78 ms detected by a flame ionization detector (FID).

Gas chromatographic applications with the dielectric barrier discharge detector.

With gas chromatography, there are many more choices for detectors when compared to other separation disciplines in analytical chemistry. The presence of sensitive and selective detectors aids in easing the separation requirements imposed on the capillary column. The current gas phase detectors, however, do not completely fulfill contemporary analytical needs.

Retention time reproducibility in comprehensive two-dimensional gas chromatography using cryogenic modulation. II. An interlaboratory study.

An interlaboratory survey was conducted to determine the reproducibility of retention times in both the first (1D) and second dimension (2D) axes of the two-dimensional separation space, using the longitudinal cryogenic modulation comprehensive two-dimensional gas chromatographic approach. Intralaboratory reproducibility has been demonstrated in part 1 of this investigation [J. Chromatogr.

Comprehensive two-dimensional gas chromatography using liquid nitrogen modulation: set-up and applications.

An improved modulation system for comprehensive two-dimensional gas chromatography (GC x GC) is presented. It is based on two-jet modulation with liquid nitrogen as cryogen. A valve system was designed to include subsequent re-heating of cooled capillary segments after modulation.

Modulation techniques and applications in comprehensive two-dimensional gas chromatography (GC x GC).

More than a decade after Phillips' first published work this article reviews recent developments in comprehensive two-dimensional gas chromatography (GC x GC). Special attention is devoted to the further development and diversity of modulation devices. These include heated sweepers, cryofocused modulators, and a variety of diaphragm valve-switching strategies.