TY - JOUR
T1 - Peak modeling approach to accurate assignment of first-dimension retention times in comprehensive two-dimensional chromatography
AU - Adcock, Jacqui
AU - Adams, Michael
AU - Mitrevski, Blagoj
AU - Marriott, Philip John
PY - 2009
Y1 - 2009
N2 - Modeling of first-dimension retention of peaks based on modulation phase and period allows reliable prediction of the modulated peak distributions generated in the comprehensive two-dimensional chromatography experiment. By application of the inverse process, it is also possible to use the profile of the modulated peaks (their heights or areas) to predict the shape and parameters of the original input chromatographic band (retention time, standard deviation, area) for the primary column dimension. This allows an accurate derivation of the first-dimension retention time (RSD 0.02 ) which is equal to that for the non-modulated experiment, rather than relying upon the retention time of the major modulated peak generated by the modulation process (RSD 0.16 ). The latter metric can produce a retention time that differs by at least the modulation period employed in the experiment, which displays a discontinuity in the retention time vs modulation phase plot at the point of the 180 degrees out-of-phase modulation. In contrast, the new procedure proposed here gives a result that is essentially independent of modulation phase and period). This permits an accurate value to be assigned to the first-dimension retention. The proposed metric accounts for the time on the second-dimension, the phase of the distribution, and the hold-up time that the sampled solute is retained in the modulating interface. The approach may also be based on the largest three modulated peaks, rather than all modulated peaks. This simplifies the task of assigning the retention time with little loss of precision in band standard deviation or retention time, provided that these peaks are not all overloaded in the first or second dimension.
AB - Modeling of first-dimension retention of peaks based on modulation phase and period allows reliable prediction of the modulated peak distributions generated in the comprehensive two-dimensional chromatography experiment. By application of the inverse process, it is also possible to use the profile of the modulated peaks (their heights or areas) to predict the shape and parameters of the original input chromatographic band (retention time, standard deviation, area) for the primary column dimension. This allows an accurate derivation of the first-dimension retention time (RSD 0.02 ) which is equal to that for the non-modulated experiment, rather than relying upon the retention time of the major modulated peak generated by the modulation process (RSD 0.16 ). The latter metric can produce a retention time that differs by at least the modulation period employed in the experiment, which displays a discontinuity in the retention time vs modulation phase plot at the point of the 180 degrees out-of-phase modulation. In contrast, the new procedure proposed here gives a result that is essentially independent of modulation phase and period). This permits an accurate value to be assigned to the first-dimension retention. The proposed metric accounts for the time on the second-dimension, the phase of the distribution, and the hold-up time that the sampled solute is retained in the modulating interface. The approach may also be based on the largest three modulated peaks, rather than all modulated peaks. This simplifies the task of assigning the retention time with little loss of precision in band standard deviation or retention time, provided that these peaks are not all overloaded in the first or second dimension.
UR - http://pubs.acs.org/doi/pdfplus/10.1021/ac900960n
U2 - 10.1021/ac900960n
DO - 10.1021/ac900960n
M3 - Article
SN - 0003-2700
VL - 81
SP - 6797
EP - 6804
JO - Analytical Chemistry
JF - Analytical Chemistry
IS - 16
ER -