Applications of resistive heating in gas chromatography: A review

Jacobs, Matthew; Hilder, Emily F.; Shellie, Robert A.

doi:10.1016/j.aca.2013.04.063

Cited by 26 publications

(11 citation statements)

References 92 publications

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“…In fact, the performance of the modulator speaks to the need to improve the performance of GC so much more efficient 1 D separations are achieved, such as providing 1 w b of ∼200−400 ms concurrently with a P M of ∼100 ms, so the sampling density is more appropriate. Recent advances in GC technology have been very promising in this regard, 29,30 such as resistively heated temperature programming, 27,31,32 with extension to micro-GC formats. 33−35 Developments in axial thermal gradient GC 36 and flow field thermal gradient GC 37 are also very promising platforms for potential integration with pulse flow valve modulation.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Development of Ultrafast Separations Using Negative Pulse Partial Modulation To Enable New Directions in Gas Chromatography

et al. 2019

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Partial modulation via a pulse flow valve operated in the negative pulse mode is developed for highspeed one-dimensional gas chromatography (1D-GC), comprehensive two-dimensional (2D) gas chromatography (GC × GC), and comprehensive three-dimensional gas chromatography (GC 3 ). The pulse flow valve readily provides very short modulation periods, P M , demonstrated herein at 100, 200, and 300 ms, and holds significant promise to increase the scope and applicability of GC instrumentation. The negative pulse mode creates an extremely narrow, local analyte concentration pulse. The reproducibility of the negative pulse mode is validated in a 1D-GC mode, where a pseudosteady-state analyte stream is modulated, and 8 analytes are baseline resolved (resolution, R s ≥ 1.5) in a 200 ms window, providing a peak capacity, n c , of 14 at unit resolution (R s = 1.0). Additionally, the pulse width, p w , of the pulse flow valve "injection" relationship to peak width-at-base, w b , resolution between peaks and detection sensitivity are studied. To demonstrate the applicability to GC × GC, a high-speed separation of a 20-component test mixture of similar, volatile analytes is shown. Analytes were separated on the second-dimension column, 2 D, with 2 w b ranging from 7 to 12 ms, providing an exceptional 2 D peak capacity, 2 n c , of ∼12 using a modulation period (P M ) of 100 ms. Next, a 12 min separation of a diesel sample using a P M of 300 ms is presented. The 1 w b is ∼4 s, resulting in a 1 n c of ∼180, and 2 w b is ∼18 ms, resulting in a 2 n c of ∼17, thus achieving a n c,2D of ∼3000 in this rapid GC × GC diesel separation. Finally, GC 3 with time-of-flight mass spectrometry (TOFMS) detection using a P M of 100 ms applied between the 2 D and 3 D columns is reported. Narrow third dimension, 3 D, peaks with 3 w b of ∼15 ms were obtained, resulting in a GC 3 peak capacity, n c,3D , of ∼35 000 in a 45 min separation.

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Section: ■ Results and Discussionmentioning

confidence: 99%

Development of Ultrafast Separations Using Negative Pulse Partial Modulation To Enable New Directions in Gas Chromatography

et al. 2019

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“…In addition, a good precision and linearity have been reported in the analysis of nitrosamines with GC-MS [49,50,51,52,53]. GC-MS technique explains the abundance of molecular composition and the amount of analyte in the sample in relation to the peak area [45,64]. Its sensitivity is based on the mass of analyte received at the detector [64,65].…”

Section: Application Of Chromatography To the Analysis Of Nitrosamines In Environmental Watersmentioning

confidence: 99%

“…GC-MS technique explains the abundance of molecular composition and the amount of analyte in the sample in relation to the peak area [45,64]. Its sensitivity is based on the mass of analyte received at the detector [64,65]. Because of sensitivity and selectivity, it is used in the selected ion monitoring (SIM) mode for the analysis of thermally stable, semi-volatile, less polar and low molecular weight nitrosamines [23,45,51,65,66].…”

Section: Application Of Chromatography To the Analysis Of Nitrosamines In Environmental Watersmentioning

confidence: 99%

Application of chromatographic techniques in the analysis of total nitrosamines in water

Yahaya

Babatunde

Olaniyan

et al. 2020

Heliyon

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The use of ozone, chloramine and chlorine dioxide for water treatment results in the formation N-nitrosamines in the treated water. These groups of chemicals and other nitrogen-containing compounds have been described as disinfection by-products (DBPs) which are known for their toxicity. Nitrosamines are a potential source of nitric oxide (NO) which can bind with metals present in the sample matrix leading to formation of metalnitrosyl complexes and dissolved metals have the potential to increase the total nitrosamines in water. This phenomenon has not received the desired attention and determination of metal-nitrosyl complexes lack standard analytical technique. Chromatography linked to various detectors is the commonest of the techniques for nitrosamine analysis but it is beset with reduced sensitivity as a result of inappropriate choice of the column. Incidentally, chromatographic techniques have not been really adapted for the analysis of metal-nitrosyl complexes. Therefore, there is need for the survey of existing techniques vis-a-vis metal-nitrosamine analysis and to suggest possible areas for method optimization.

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“…The modulator consecutively and systematically collects analytes as they are eluted from the first dimension column and delivers them to the second dimension column . There are many modulation possibilities for comprehensive two-dimensional gas chromatography (GC × GC): resistive heating of painted zones of modulator capillary, rotational movement of a slotted heater, , longitudinal movement of a cold trap, − cryogen jets with or without the combination of a hot jet, resistive heating with or without a cryogen trap, − and more . In contrast, comprehensive two-dimensional liquid chromatography (LC × LC) has not been demonstrated in online-mode without use of switching valves.…”

mentioning

confidence: 99%

“…High temperatures are commonly employed in LC to achieve faster separations, improve selectivity and resolution, and reduce backpressure, ,− although typically at isothermal conditions. Since the adaptation of low thermal mass (LTM) resistive heating from GC − , to LC, there have been a number of studies on thermal gradient elution − ,− and temperature pulsing for manipulating discrete sections of the separation. , The LTM technology was also employed as a modulator for offline LC × LC by Verstraeten et al where a capillary trap segment was temperature cycled to facilitate modulation and fraction collection from the first dimension.…”

mentioning

confidence: 99%

Longitudinal On-Column Thermal Modulation for Comprehensive Two-Dimensional Liquid Chromatography

Creese

Creese²,

Foley

et al. 2016

Anal. Chem.

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Longitudinal on-column thermal modulation for comprehensive two-dimensional liquid chromatography is introduced. Modulation optimization involved a systematic investigation of heat transfer, analyte retention, and migration velocity at a range of temperatures. Longitudinal on-column thermal modulation was realized using a set of alkylphenones and compared to a conventional valve-modulator employing sample loops. The thermal modulator showed a reduced modulation-induced pressure impact than valve modulation, resulting in reduced baseline perturbation by a factor of 6; yielding a 6-14-fold improvement in signal-to-noise. A red wine sample was analyzed to demonstrate the potential of the longitudinal on-column thermal modulator for separation of a complex sample. Discrete peaks in the second dimension using the thermal modulator were 30-55% narrower than with the valve modulator. The results shown herein demonstrate the benefits of an active focusing modulator, such as reduced detection limits and increased total peak capacity.

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Applications of resistive heating in gas chromatography: A review

Cited by 26 publications

References 92 publications

Development of Ultrafast Separations Using Negative Pulse Partial Modulation To Enable New Directions in Gas Chromatography

Development of Ultrafast Separations Using Negative Pulse Partial Modulation To Enable New Directions in Gas Chromatography

Application of chromatographic techniques in the analysis of total nitrosamines in water

Longitudinal On-Column Thermal Modulation for Comprehensive Two-Dimensional Liquid Chromatography

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