Effect of First-Dimension Undersampling on Effective Peak Capacity in Comprehensive Two-Dimensional Separations
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- 作者：Joe M. Davis ; Dwight R. Stoll ; Peter W. Carr
- 刊名：Analytical Chemistry
- 出版年：2008
- 出版时间：January 15, 2008
- 年：2008
- 卷：80
- 期：2
- 页码：461 - 473
- 全文大小：209K
- 年卷期：v.80,no.2(January 15, 2008)
- ISSN：1520-6882
文摘
The objective of this work is to establish a means ofcorrecting the theoretical maximum peak capacity ofcomprehensive two-dimensional (2D) separations to account for the deleterious effect of undersampling first-dimension peaks. Simulations of comprehensive 2Dseparations of hundreds of randomly distributed sampleconstituents were carried out, and 2D statistical overlaptheory was used to calculate an effective first-dimensionpeak width based on the number of observed peaks inthe simulated separations. The distinguishing feature ofthis work is the determination of the effective first-dimension peak width using the number of observedpeaks in the entire 2D separation as the defining metricof performance. We find that the ratio of the averageeffective first-dimension peak width after sampling to itswidth prior to sampling (defined as <
rs/beta2.gif" BORDER=0 ALIGN="middle">>) is a simplefunction of the ratio of the first-dimension sampling time(ts) to the first-dimension peak standard deviation priorto sampling (1rs/sigma.gif" BORDER=0 >): <rs/beta2.gif" BORDER=0 ALIGN="middle">> = 
ribe/journals/ancham/80/i02/eqn/ac071504je10001.gif"> This is validfor 2D separations of constituents having either randomlydistributed or weakly correlated retention times, over therange of 0.2 
ts/1rs/sigma.gif" BORDER=0 > 16. The dependence of <rs/beta2.gif" BORDER=0 ALIGN="middle">> onts/1rs/sigma.gif" BORDER=0 > from this expression is in qualitative agreement withprevious work based on the effect of undersampling onthe effective width of a single first-dimension peak, butpredicts up to 35% more broadening of first-dimensionpeaks than is predicted by previous models. This simpleexpression and accurate estimation of the effect of undersampling first-dimension peaks should be very usefulin making realistic corrections to theoretical 2D peakcapacities, and in guiding the optimization of 2D separations.
rs/beta2.gif" BORDER=0 ALIGN="middle">>) is a simplefunction of the ratio of the first-dimension sampling time(ts) to the first-dimension peak standard deviation priorto sampling (1rs/sigma.gif" BORDER=0 >): <rs/beta2.gif" BORDER=0 ALIGN="middle">> = ts/1rs/sigma.gif" BORDER=0 > 16. The dependence of <rs/beta2.gif" BORDER=0 ALIGN="middle">> onts/1rs/sigma.gif" BORDER=0 > from this expression is in qualitative agreement withprevious work based on the effect of undersampling onthe effective width of a single first-dimension peak, butpredicts up to 35% more broadening of first-dimensionpeaks than is predicted by previous models. This simpleexpression and accurate estimation of the effect of undersampling first-dimension peaks should be very usefulin making realistic corrections to theoretical 2D peakcapacities, and in guiding the optimization of 2D separations.