Instrumental contributions to band broadening in gas chromatography

Fluidic and syringe injection study by peak shape analysis

“…From peak skewness and excess, different extracolumn band broadening models (e.g. exponential dilution) can be checked and their characteristic parameters evaluated (6,9,13,16,17). In fact, the extracolumn effect variances are independent and additive (5,18,19)…”

Effect of detector nonlinearity on the height, area, width, and moments of chromatographic peaks based on a Gaussian model

“…There is essentially no quantitative literature on the general effect of nonlinear detector response (Figure 1) on chromatographic peaks, although qualitative discussions of the phenomenon in the context of thermal conductivity detectors have appeared (1)(2)(3). In contrast, many papers (4)(5)(6), reviews (7)(8)(9)(10)(11), and monographs (12,13) on chromatographic detectors have described in detail the effect of nonideal transient de-tector and electronic response on peak height, area, variance, and shape. Since many chromatographic detectors have rather restricted ranges of linearity, we believe that the effect of nonlinear response is chromatographically significant.…”

“…In this initial paper on detector nonlinearity effects on peak shape, I have therefore arbitrarily opted to assess the effect of the nonlinearity in the absence of the complicating effect of peak asymmetry. In the case of a perfectly GaussiEm peak, the various moments are as follows (31,32): i* = v^aC° (6) mi* = tR (7) m2* = 2 In all the work which follows, a moment designated with an asterisk will refer to a pure Gaussian peak. It should be noted that all odd central moments of any symmetric peEik, Gaussian or otherwise, are exactly zero.…”

Efficiency of short, thick-film capillary columns in gas chromatography with sulfur chemiluminescence detector for the separation of sulfur compounds—a best performance study

“…But while using a short capillary column with high linear carrier gas velocity, the extra-column contribution to the HETP becomes more important. The contribution of instrumental effects to band-broadening has been evaluated by many authors [14][15][16][17][18]. Earlier publications about extra-column contributions were mainly concerned about the injection system [ 19,20], detector geometry [21 ], make-up gas flow rate [22], and the time constant of the amplifier and data processing [ 15,21 ].…”