Electrically Heated, Air-Cooled Thermal Modulator and at-Column Heating for Comprehensive Two-Dimensional Gas Chromatography

Libardoni, Mark; Waite, J. H.; Sacks, Richard

doi:10.1021/ac040161b

Cited by 40 publications

(38 citation statements)

References 43 publications

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“…Future research will necessarily be devoted to the introduction of systems with low operational costs. For example, an apparently robust electrically heated and air-cooled thermal modulator, requiring no cryogenic materials, has been recently described (Libardoni, Waite, & Sacks, 2005). It is the authors' opinion that such a direction, related to the origins of the method, appears to be one worth taking.…”

Section: A Modulation Processmentioning

confidence: 99%

Comprehensive two‐dimensional gas chromatography‐mass spectrometry: A review

Mondello

Tranchida

Dugo

et al. 2008

Mass Spectrometry Reviews

382

216

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Although comprehensive two-dimensional gas chromatography (GC Â GC) has been on the scene for more than 15 years, it is still generally considered a relatively novel technique and is yet far from being fully established. The revolutionary aspect of GC Â GC, with respect to classical multidimensional chromatography, is that the entire sample is subjected to two distinct analytical separations. The resulting enhanced separating capacity makes this approach a prime choice when GC analysts are challenged with highly complex mixtures. The combination of a third mass spectrometric dimension to a GC Â GC system generates the most powerful analytical tool today for volatile and semi-volatile analytes. The present review is focused on the rather brief, but not scant, history of comprehensive two-dimensional GC-MS: the first experiments were carried out at the end of the 1990s and, since then, the methodology has been increasingly studied and applied. Almost all GC Â GC-MS applications have been carried out by using either a time-of-flight or quadrupole mass analyzer; significant experiments relative to a variety of research fields, as well as advantages and disadvantages of the MS systems employed, are discussed. The principles, practical and theoretical aspects, and the most significant developments of GC Â GC are also described. #

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Section: A Modulation Processmentioning

confidence: 99%

Comprehensive two‐dimensional gas chromatography‐mass spectrometry: A review

Mondello

Tranchida

Dugo

et al. 2008

Mass Spectrometry Reviews

382

216

View full text Add to dashboard Cite

show abstract

“…As a result, the main criterion for evaluating modulator performance was the full width at half maximum height (FWHM) of the detected peaks. The modulator performance can be directly measured by replacing the second column with non-retaining guard column (Libardoni et al 2005). However, weakly retained compounds, such as n-alkanes, exhibit minimal diffusional broadening in the second column and therefore offer a good approximation to peak widths exiting the second column.…”

Section: Requirements For the Ideal Modulator For In-situ Measurementsmentioning

confidence: 99%

“…The most commonly used modulators in atmospheric chemistry have been cryogenic and valvebased modulators (Hamilton 2010). However, because robustness, simplicity, and low operating costs are attractive features, recent work has focused on the development of improved versions of this type of modulator (Libardoni et al 2005(Libardoni et al , 2006(Libardoni et al , 2010Panić et al 2011). Successful single-stage modulation has been reported using recirculated cold air (−30…”

Section: Requirements For the Ideal Modulator For In-situ Measurementsmentioning

confidence: 99%

Thermal Desorption Comprehensive Two-Dimensional Gas Chromatography: An Improved Instrument for In-Situ Speciated Measurements of Organic Aerosols

Worton

Kreisberg

Isaacman-VanWertz

et al. 2012

Aerosol Science and Technology

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The organic fraction is a major constituent of fine atmospheric particulate matter, though its chemical composition is complex and not well understood. This complexity presents an extreme analytical challenge and is well suited to analysis by comprehensive twodimensional gas chromatography (GC × GC). This has recently been coupled to a thermal desorption aerosol gas (TAG) chromatograph instrument to provide improved in-situ, hourly measurement of speciated organic compounds in atmospheric aerosols (2D-TAG). The original 2D-TAG instrument utilized a flame ionization detector, dual-stage modulator, and a second-dimension column that proved to be thermally unstable under optimal analysis conditions, which limited compound identification, instrument robustness, and time resolution. In this paper, we address these shortcomings by demonstrating the successful integration of a time-of-flight mass spectrometer (TOFMS), development of a simplified hybrid thermo-pneumatic modulator, and incorporation of a more thermally stable secondary column. These improvements resulted in an instrument capable of providing detailed speciated information of organic tracer compounds in atmospheric aerosols in near real time.

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“…To this end, an air-cooled, resistively heated single-stage thermal modulator has been described recently [19]. The device uses a commercially available stationary-phase coated metal capillary tube as the modulator.…”

Section: Introductionmentioning

confidence: 99%

“…This report describes the design and performance evaluation of a transportable GC6GC that uses no convection oven and requires no consumables other than electric power, carrier gas, and gas for the flame ionization detector (FID). The thermal modulator is based on the previously described single-stage device [19] except liquid rather than air cooling is used. In addition, a programmable power supply is used for modulator heating that allows for on-the-fly changes in the modulator heating profile during an analysis.…”

Section: Introductionmentioning

confidence: 99%

At-column heating and a resistively heated, liquid-cooled thermal modulator for a low-resource bench-top GC×GC

et al. 2006

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A transportable GC x GC instrument is under development for on-site applications that would benefit from the enhanced resolution and powers of detection, which can be achieved by this method. In the present study, a low-resource GC x GC instrument using an electrically heated and liquid-cooled single-stage thermal modulator that requires no cryogenic materials is evaluated. The instrument also uses at-column heating, thus eliminating the need for a convection oven to house the two columns. The stainless-steel modulator tube is coated with PDMS, which can be heated to 350 degrees C for sample injection into the second-dimension column. The modulator is cooled to -30 degrees C by a 100 mL/min flow of PEG by means of a commercial liquid chiller and a small recirculating pump. Resistive heating of the modulator tube is provided by a programmable power supply, which uses a voltage program that results in increasing modulator temperature during an analysis. This, together with more rapid cooling by the use of a liquid cooling medium, results in reduced solute breakthrough following each heating cycle as the modulator cools to a temperature where quantitative trapping resumes. As a result, modulated peak widths at half-height of less than 40 ms are observed. Design and performance details are presented along with chromatograms of gasoline and an essential oil sample.

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Electrically Heated, Air-Cooled Thermal Modulator and at-Column Heating for Comprehensive Two-Dimensional Gas Chromatography

Cited by 40 publications

References 43 publications

Comprehensive two‐dimensional gas chromatography‐mass spectrometry: A review

Comprehensive two‐dimensional gas chromatography‐mass spectrometry: A review

Thermal Desorption Comprehensive Two-Dimensional Gas Chromatography: An Improved Instrument for In-Situ Speciated Measurements of Organic Aerosols

At-column heating and a resistively heated, liquid-cooled thermal modulator for a low-resource bench-top GC×GC

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