Dynamic thermal gradient gas chromatography

Moving thermal gradients in gas chromatography

“…The focusing effect of TGGC to correct for band broad-373 ening caused by wide injection bands was noted by Contreras et al[11].Figure 5374 demonstrates how fast this occurs. Because of the quick response, it is reasonable to 375 posit that in-column irregularities of the stationary phase may have a reduced effect 376 on band broadening and resolution using TGGC.…”

“…It is reasonable to expect, therefore, that 68 the latter two can be programmed to avoid inefficiencies of the separation process in 69 TPGC due to the higher than desirable temperatures of the analyte during transport. 70 Previously we have shown that the focusing property of TGGC can decrease band 71 broadening that results from poor injection of analytes into the column relative to 72 TPGC[10] [11]. However, any other relative advantages of TGGC relative to TPGC as Here, we assume that the model of transport of the analyte is essentially a one-91 dimensional model.…”

“…Consequently, the heated analyte was not adequately cooled to create a thermal gradient at room temperature in a 20cm column unless the mobile phase velocity was reduced to below 15cm/s. 11 The relationship between C 12 and the "near neighbor" is as follows: k= 6.3972 vs 5.9019, K= 0.1352 vs 0.1449, ∆H= 11,416 vs 11,521 and C = -12.5075 vs -12.7202 for C 12 and the near neighbor, respectively. Figure 2B shows that for lower mobile 284 phase velocities, the pattern observed in Figure 2A holds for values of the gradient 285 velocity between the lowest and middle ranges.…”

New Opportunities and Challenges of Smart Polymers in Post‐Translational Modification Proteomics

“…However, thermoresponsive polymers are seldom used in the field of chromatographic separation because the local column temperature and the thermal gradient cannot be modulated dynamically in conventional chromatography. In 2013, Contreras, et al resolved this issue by constructing a dynamic‐thermal‐gradient gas‐chromatography separation system, which contained an individually resistively heated component ( Figure a) and a continuous forced air convection cooling component. This elaborate system could provide dynamic and repetitive thermal gradients with customized profiles, which further facilitated the accurate control of the retention behaviors of analytes on gas chromatography.…”

Evaluation of injection methods for fast, high peak capacity separations with low thermal mass gas chromatography

“…A recent review by Tranchida and Mondello [18] discusses the use of microbore capillary columns for fast GC, and another recent review by Wang et al [19] outlines the use of resistive heating for fast GC. Other techniques for rapid column heating, such as thermal gradient chromatography [20][21][22][23] have shown promise as novel technologies in the fast GC field. The results we present herein, as well as the results presented in previous references have important implications for two-dimensional gas chromatography (GC × GC or GC-GC) [24][25][26].…”